graphite.pc.in: Use '@' for the variables which are to be replaced.
CMakeLists.txt: Add prefix variable to be set to CMAKE_INSTALL_PREFIX.
CMakeLists.txt: Add @ONLY argument in configure_file. So only variables
which are prefixed with '@' will be replaced only. This helps to retain
Libs and Cflags variables.
Changes:
@ONLY
argument in configure_file. So only variables which are prefixed with '@' will be replaced only. This helps to retain Libs and Cflags variables.