imlib2: upgrade to use pkg-config for freetype2 support

* convert from old svn repo to new (legacy) git repo
* fixed upstream:
  commit fe82b9760c7ceb25747c6e634bc827b4cc8ecabd
  Author: Kim Woelders <kim@woelders.dk>
  Date:   Thu Jul 4 20:08:53 2013 +0200

    Autofoo updates.

    - Eliminate deprecated AC_TRY_CPP.
    - Use pkg-config in stead of freetype-config to get freetype info.
    - Eliminate my_includes/my_libs.
    - Clean up include paths.

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>