TUNDRA_NO_BOOST - make Boost an optional dependency

-re: #595 
-rationale: Boost is huge (around 70k files, takes around 2 gigs of disk space) and unneeded - the used features can be found already from the C++ standard library (TR1 and/or C++11) and Qt
-windows-build-deps.cmd has USE_BOOST variable that is used to configure whether kNet, AssImp and Ogre use Boost. Ogre uses Intel Thread Building Blocks for threading if USE_BOOST is FALSE
-core magic: https://github.com/LudoCraft/Tundra/blob/c1b2103540626c5ac6c9bdae349f4868ecdf5ab7/src/Core/TundraCore/Framework/CoreTypes.h
-built, run, and tested on Windows Vista/7/8 (both Boost enabled and disabled) with VC9SP1 and VC10SP1, and on OS X 10.6.8 (Boost enabled) with GCC 4.2.1

TODOs now:
1) Tundra(d).exe freezes mysteriously when the application is shut down. This freeze doesn't occur when running TundraConsole(d).exe. Need to take a look into the ShellInputThread class (converted it from boost::thread to QThread)
2) Add regex validation check to HttpAssetProvider::ParseHttpData
And later on:
3) Introduce USE_BOOST variable to Ubuntu and OS x build scripts
4) Consider building TBB instead of using prebuilt package

I would suggest that as a short term plan TUNDRA_NO_BOOST is false by default, as a medium term plan TUNDRA_NO_BOOST would be made TRUE by default, and as a long term plan Tundra should not have a Boost dependency at all and TUNDRA_NO_BOOST configuration could be removed