pull in nickyd's changes to APR and LLCEFLib (Dullahan) for MAINT-6116 Console window appears breifly for Flash sites

Pull in improvements to LLProcess termination via a commit from Nat Linden here: https://bitbucket.org/rider_linden/doduo-viewer/commits/4f39500cb46e879dbb732e6547cc66f3ba39959e?at=default

Add back the missing pieces and updated code for the example plugin.  It was useful during testing SLPlugin changes. Not shipped with release versions of viewer

Remove the scary 32bit exception handler that patches kernel32.dll since it was (a) scary, (b) didn't work on 64 bit and (c) likely the cause of a lot of anti-virus false positives

Partial fix for MAINT-7236 Web content does not always respect UI Size preference (pull in new version of Dullahan with improved support)

Fix for MAINT-7227 Drop down lists do not close after use in internal web browser. (Surprisingly large amount of changes and new version of Dullahan to support this fix)

 fix for MAINT-6998 64bit viewer installs to Program Files (x86) by default. - this change also fixes MAINT-5365 Windows viewer uninstall icon is system default not SL logo

The previous LLSafeHandle<T> implementation declares a static data member of
the template class but provides no (generic) definition, relying on particular
specializations to provide the definition. The data member is a function
pointer, which is called in one of the methods to produce a pointer to a
"null" T instance: that is, a dummy instance to be dereferenced in case the
wrapped T* is null.

Xcode 8.3's version of clang is bothered by the call, in a generic method,
through this (usually) uninitialized pointer. It happens that the only
specializations of LLSafeHandle do both provide definitions. I don't know
whether that's formally valid C++03 or not; but I agree with the compiler: I
don't like it.

Instead of declaring a public static function pointer which each
specialization is required to define, add a protected static method to the
template class. This protected static method simply returns a pointer to a
function-static T instance. This is functionally similar to a static
LLPointer<T> set on demand (as in the two specializations), including lazy
instantiation.

Unlike the previous implementation, this approach prohibits a given
specialization from customizing the "null" instance function. Although there
exist reasonable ways to support that (e.g. a related traits template), I
decided not to complicate the LLSafeHandle implementation to make it more
generally useful. I don't really approve of LLSafeHandle, and don't want to
see it proliferate. It's not clear that unconditionally dereferencing
LLSafeHandle<T> is in any way better than conditionally dereferencing
LLPointer<T>. It doesn't even skip the runtime conditional test; it simply
obscures it. (There exist hints in the code that at one time it might have
immediately replaced any wrapped null pointer value with the pointer to the
"null" instance, obviating the test at dereference time, but this is not the
current functionality. Perhaps it was only ever wishful thinking.)

Remove the corresponding functions and static LLPointers from the two classes
that use LLSafeHandle.

MAINT-7245 Use Experience Box in LSL Editor will not show as checked if containing object is in another region

When a 'family' code isn't recognized, for instance, report the family code.
That should at least clue us in to look up and add an entry for the relevant
family code.

Fix for MAINT-7131 Unable to start the x64 Viewer on Windows 8.1 x64.  This appears to be because two of the MS DLLs we ship with the 64 bit viewer are 32bit. Manually replacing them with their 64 bit equivalents allowed the viewer to start on Windows 8.1.  The change forces the cmake file which copies the DLLs to look in C:\windows\SysWOW64 for 32 bit versions and C:\windows\system32 for 64 bit versions. (yes really).

Additional work on : Fix for MAINT-7054 Viewer Crashed when I used Japanese IM. (Drake and Appurist convinced me my initial solution was non-optimal)