Changes 0.2.8:
Another minor maintenance release. Most fixes were related to the build system.
But as always we have many(!) new lens profiles.
Updated graphics/lensfun to 0.2.8
Use the compiler front-end to generate shared libraries on OSX - the
native linker uses different arguments compared to GNU ld.  Fixes various
builds.

Bump version to 20131025.
Updated pkgtools/bootstrap-mk-files to 20131025
Some Linux systems now use DT_RUNPATH, so match it here as well.
GC