* add new function vcpkg_fixup_pkgconfig
* make message with changed files a debug_message
* add two more cases to the debug *.pc files
* comment out prefix.
use --define-variable=prefix=INSTALL_PATH
* changed the comment header.
* add missing word
* finish vcpkg_fixup_pkgconfig.cmake
* Update vcpkg_fixup_pkgconfig.cmake
Note: since CMake is run in script mode the description of VCPKG_FIXUP_PKGCONFIG_CALLED cannot be viewed
* transfer changes from x windows pr
* fix typo in regex
* make the regex comment aware
make pc files relocatable by using ${pcfiledir} in prefix
tested with x window pr
