lensfun: Move URLs to sourceforge.

via http://lensfun.berlios.de/
Lensfun moved to Sourceforge!

BerliOS will shut down its service at the end of April 2014. Therefore, we moved
everything to Sourceforge and at the same time we took the opportunity to switch
the version control system to git.

Signed-off-by: Evan McClain <aeroevan@gmail.com>