libfreeimage: new package

FreeImage is an Open Source library project for developers who would like to
support popular graphics image formats like PNG, BMP, JPEG, TIFF and others as
needed by today's multimedia applications.

See: http://freeimage.sourceforge.net



[Thomas:
  - add hash file
  - add dependency on !BR2_STATIC_LIBS, since the build system of
    libfreeimage always tries to build a shared library.]

Signed-off-by: Rémi Rérolle <remi.rerolle@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>