Makefile:
- Add a new target that makes a single libwebm.a instead of building
separate muxer and parser libraries.
- Update sample targets accordingly.
Visual Studio:
- Use a single project for muxing and parsing, and build a single library
name libwebm.lib.
- Update code generation settings (DLL -> static runtimes).
- Use C7 debug information format (instead of PDB)
- Disable minimal rebuild (C7 use causes warning otherwise).
Change-Id: Ie221d4ee02c93f98f2521757c08b75ecbf75f54f
