Fixes OSX Build issues.

CMakeLists.txt changes:

 * Moved compiler configuration above gtest include
 * Forced libc++ when building with clang

src/EntityManager.hpp changes:

 * Switched stdint include string -- clang likes this one better.

src/World.hpp

 * Members requiring a template argument need the template keyword
   after the . or -> and before the member symbol.

All tests now pass on OSX with the following build process:

    mkdir build && cd build && cmake .. && cmake --build . && ./testrunner
Removed extraneous include

I'd forgotten to strip this include out of the commit -- I was forcing a particular version of boost on my machine while building this.
Merge pull request #15 from aberghage/fix-osx-build

Fixes OSX Build issues.
Added constructComponent() method and tests.

Added constructComponent() method to construct a component from its
data instead of requiring a component to be passed in by the user.
Rewrote constructComponent to call addComponent.

The body of constructComponent was almost identical to addComponent
so it was rewritten to call addComponent.
Replaced VectorTuple with std::tuple of vectors

Replaced VectorTuple class with and std::tuple of std::vectors.
Removed unneeded VectorTuple.hpp and vectorTupleTests.cpp.
Merge branch 'tuple_stuff' into dev

Conflicts:
	src/EntityManager.hpp
Cleanup after merge.