Fixed `winfo` macro.
Removed forced CMake configuration options.
Fixed include dirs CMake variable inclusion.
Ensured file and project deps were in order.

  * Added a GUI IDE project label.
  * Ensured that sources were automoc-ed by Qt4.
Added documentation to plugin macros.
Improved plug-in library discovery.

  * Fixed UUID conversion to sane ID string.
  * Ensured full Linux path discovery for libraries.
  * Introduced more documentation.
Updated logic for plugin interface detection.
Updated plugin code.

  - src/Wintermute/plugin.cpp
    * Updated ctor with new private arguments.
  - src/Wintermute/private/plugin.hpp
    * Added logic for loading plug-in binaries.
    * Added logic for obtianing plug-in interfaces.
Added macro for Wintermute plugin declaration.
Moved logic for plug-in loading into prv data.