Add static_initializer
Fix MSVC workaround in basic_seconds_clock
Use std::thread instead of boost::thread
Insures the visual studio file is always described
Allows scons vcxproj to work on all systems

Changes along the way:
* Makes itemlist work in Python 3
* Makes the toolchain loop more straightforward
* Removes an old variable
* Prevents checking nonexistant enviro vars
* Prevents pkg-config protobuf env vars if not clang/gcc
* Removes tabs
* Doesn't use any pkg-config enviro vars unless clang/gcc
Merge pull request #4 from evhub/develop-scons

Develop scons