Faster Runtime Compiles and Improved Compiler support

Recent code changes have concentrated on getting faster runtime compiles, and improving compiler support.

• The Posix compiler (for Linux and OS X) now outputs intermediates. Motivated by a request from Github user procedural, I finally got around to getting this to work. I've seen up to a 2x performance boost on repeat compiles, and small compile times are now much shorter than a second. Developers should be aware that they may need to clean their runtime Intermediate folder via the IRuntimeObjectSystem::CleanObjectFiles() function.
• Visual Studio 2015 is now fully supported from both upgrading the solution or generating with cmake. After reading Bruce Dawson's excellent post on /DEBUG:FASTLINK I've added support for this to compiles, with generated pdb's being much smaller and runtime compiles faster. Thanks to github user Ashalah for spotting I had the VS2015 version number incorrect as MS skipped 13!
• CMake support for OS X has been added, so developers can use this instead of the included XCode project if needed.
• Runtime dependencies have been extended to support arbitrary file and extensions. See the documentation on the wiki for more details.
• Added cmake install support from Github user kubaroth.

Runtime Compiled C++ at Develop:Brighton 2015

I'll be attending Develop:Brighton 2015 (but won't be giving a talk like we did in 2012), so if anyone there would like to meet up and chat about RCC++ then please drop me a line through my twitter account @dougbinks or email me through doug@enkisoftware.com.

Per-project build intermediate directories and cmake additions.

The latest additions to Runtime Compiled C++ improves cmake support by fixing a few issues with Visual Studio and QtCreator on Windows, and adds per project build intermediate directories.

Developers can now call RuntimeObjectSystem::SetIntermediateDir( const char* path_, unsigned short projectId_ = 0 ); to set a path for the given project id. The main use for this is when a project might include the same source file but compile it with different settings.

Additionally the optimization level used is automatically added to the intermediate directory, so there is no need to clean a build when switching from debug to release and vice versa.

As usual, see the Pull Request for more details.