MAINT-8991: only escape log message characters once, add unit test
remove extra log line created by LL_ERRS
document that tags may not contain spaces

A shocking number of LLSingleton subclasses had public constructors -- and in
several instances, were being explicitly instantiated independently of the
LLSingleton machinery. This breaks the new LLSingleton dependency-tracking
machinery. It seems only fair that if you say you want an LLSingleton, there
should only be ONE INSTANCE!

Introduce LLSINGLETON() and LLSINGLETON_EMPTY_CTOR() macros. These handle the
friend class LLSingleton<whatevah>;
and explicitly declare a private nullary constructor.

To try to enforce the LLSINGLETON() convention, introduce a new pure virtual
LLSingleton method you_must_use_LLSINGLETON_macro() which is, as you might
suspect, defined by the macro. If you declare an LLSingleton subclass without
using LLSINGLETON() or LLSINGLETON_EMPTY_CTOR() in the class body, you can't
instantiate the subclass for lack of a you_must_use_LLSINGLETON_macro()
implementation -- which will hopefully remind the coder.

Trawl through ALL LLSingleton subclass definitions, sprinkling in
LLSINGLETON() or LLSINGLETON_EMPTY_CTOR() as appropriate. Remove all explicit
constructor declarations, public or private, along with relevant 'friend class
LLSingleton<myself>' declarations. Where destructors are declared, move them
into private section as well. Where the constructor was inline but nontrivial,
move out of class body.

Fix several LLSingleton abuses revealed by making ctors/dtors private:

LLGlobalEconomy was both an LLSingleton and the base class for
LLRegionEconomy, a non-LLSingleton. (Therefore every LLRegionEconomy instance
contained another instance of the LLGlobalEconomy "singleton.") Extract
LLBaseEconomy; LLGlobalEconomy is now a trivial subclass of that.
LLRegionEconomy, as you might suspect, now derives from LLBaseEconomy.

LLToolGrab, an LLSingleton, was also explicitly instantiated by
LLToolCompGun's constructor. Extract LLToolGrabBase, explicitly instantiated,
with trivial subclass LLToolGrab, the LLSingleton instance.

(WARNING: LLToolGrabBase methods have an unnerving tendency to go after
LLToolGrab::getInstance(). I DO NOT KNOW what should be the relationship
between the instance in LLToolCompGun and the LLToolGrab singleton instance.)

LLGridManager declared a variant constructor accepting (const std::string&),
with the comment:
// initialize with an explicity grid file for testing.
As there is no evidence of this being called from anywhere, delete it.

LLChicletBar's constructor accepted an optional (const LLSD&). As the LLSD
parameter wasn't used, and as there is no evidence of it being passed from
anywhere, delete the parameter.

LLViewerWindow::shutdownViews() was checking LLNavigationBar::
instanceExists(), then deleting its getInstance() pointer -- leaving a
dangling LLSingleton instance pointer, a land mine if any subsequent code
should attempt to reference it. Use deleteSingleton() instead.

~LLAppViewer() was calling LLViewerEventRecorder::instance() and then
explicitly calling ~LLViewerEventRecorder() on that instance -- leaving the
LLSingleton instance pointer pointing to an allocated-but-destroyed instance.
Use deleteSingleton() instead.

 1) stripped off attachment field;
 2) made logos (group's, sender's, etc) in expanded view the same size as in condensed view;
 3) turned on notification showing upon click;
 4) fixed cropped right border of Invite and Transactions notifications;
 5) enabled "Collapse All" button;
 6) stripped off unnecessary icons.

Works:
1) All new notices shown on "Invites" tab of new floater "NOTIFICATIONS TABBED" in condensed view
To be done:
1) Show other types of notices, like transactions and system
2) Separate notices between tabs "Invites", "System", "Transactions"
3) Design full notice view (in addition to condensed view)

replace llinfos, lldebugs, etc with new LL_INFOS(), LL_DEBUGS(), etc.

Set UnreadIMs icon to visible if messages were sent while offline.

CHUI-337 FIXED: To avoid confusion with a classes "...conversation..." and in accordance with the naming convention in the project, some classes and corresponding files should be renamed:
LLIMConversation -> LLFloaterIMSessionTab
LLIMFloater -> LLFloaterIMSession
LLNearbyChat -> LLFloaterIMNearbyChat
LLIMFloaterContainer -> LLFloaterIMContainer
LLNearbyChatBarListener -> LLFloaterIMNearbyChatListener
LLNearbyChatHandler -> LLFloaterIMNearbyChatHandler

CHUI-374 ADD. FIX, CHUI-442 FIXED (Nearby chat is torn off and cannot be docked if nearby chat is received while conversation floater is closed) - implement. lazy creating of container

CHUI-138 : Suppress chiclets for conversations when using tabbed UI; Make sure list is cleaned up on close

CHUI-120 WIP Added starting ad hoc conference in the same floater as P2P chat, after adding more participants.
- Added a parameter to LLAvatarActions::startConference() and LLIMMgr::addSession() to pass the uuid of a P2P IM floater which should be used to start a new conference in it.
- In LLChicletBar::sessionRemoved() we don't close the IM floater if it is going to be re-used for a new conference.

EXP-1758 WIP Progress spinner not shown during merketplace synch if Merchant Outbox floater was previously minimized
rewrote layout_stack resizing logic to be symmetrical

- Don't let chiclet list left side to be out of chiclet_container

- Now chiclet bar adjusts its width with Mini-Location bar

- Floaters dock to chiclets at the bottom.
- Floaters docking region limited to non-toolbar view.
- Chiclet bar is positioned between the right toolbar and the minimized floaters stacked at the top left corner by default.