Merge 1537.

Build new mesa on dfly


git-svn-id: https://trillian.chruetertee.ch/svn/ports/branches/experimental@1538 058c260c-8361-11dd-a0ac-aa2bafec7d09
Merge 1539.

Update mesa to 10.3.1.


git-svn-id: https://trillian.chruetertee.ch/svn/ports/branches/experimental@1540 058c260c-8361-11dd-a0ac-aa2bafec7d09