Updates and enhancements

[bscottm]

This looks like a significant rewrite. It's not, just a lot of new code. Read through README.md.

Extended functionality in many directions, such as tracking the CMake project's top-level source directory and associating the build directory, project configuration arguments (architecture, toolset, flags) with the top-level source directory.

Extracts and caches capabilities from the cmake-project-cmake-command's output. Default for cmake-project-cmake-command is "cmake".

Enhanced cmake-project-find-root directory search strategy. Seed directories:

• (project-root (project-current)), if project.el loaded
• Directory component of buffer's file name, if not nil
• Dired's dired-directory (as a last resort)

New user variables:

• cmake-project-cmake-command: The CMake command.
• cmake-project-build-config: Default build configuration ("Debug")

[bscottm]

Found a couple of last minute items to fix from byte-compile's output.