Linking/Include options sensitive to certain source files

Special linking/include options may optionally be tied to a particular source file, which should include those linking/include options on all source files up the dependency tree.

Example:
`./build -buildopts:"World/PhysicsWorld/PhysicsWorld.cpp:-I/.../dartsim/include -L/../dartsim/lib -framework GLUT -ldart_gui ..."`

Or perhaps we should be performing all linking/including on all files...