Get rid of that ugly '#pragma clang diagnostic ignored "-Wdelete-incomplete"' by making sure the delete always happens inside llview.cpp, where the type of LLView is known.

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.

LLView::childFromPoint(), which is declared to return LLView*, contained a
code path that could 'return false'. This is blatantly wrong. Why has it
compiled on our other compilers so far?

Initial support for keyboard (in progress) but includes many viewer changes to plumb in Key Up events

Update to build on Xcode 6.0: more removal of unused const variables [-Wunused-const-variable] and member variables

- Removed logging for MAINT-3555
- Added NULL guard to fix MAINT-3703 (hopefully)

- Removed a lot of logging code to reduce application close time

much cleanup of vector math
also made Stretch Both Sides checkbox clickable via label

changed claimMem and disclaimMem behavior to not pass through argument
added more mem tracking stats to floater_stats

removed complicated and unnecessary fast timer gapless handoff logic (it should be gapless anyway)
improved MemTrackable API, better separation of shadow and footprint
added memory usage stats to floater_stats.xml

another attempt to move mem stat into base class

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

stat definition as they don't work on gcc/clang

also, removed LLTrace::init and cleanup
removed derived class implementation of memory stat for LLMemTrackable
is automatic now

renamed LLView::handleVisibilityChange to onVisibilityChange to reflect
standard naming conventions for handlers vs. reactors

collapsed Orientation enums to all use LLView::EOrientation
added ability to display stat bar horizontally

Count becomes CountStatHandle
Count.sum becomes sum(Count, value), etc.