GCC 4.2 in FreeBSD 8.X/9.X base is now too old to compile OpenEXR, so
GCC-based systems will upgrade to the default ports compiler (GCC 4.7
currently.)

Add two patches to OpenEXR to permit building it in a live system with
the older OpenEXR version installed. Bug report filed to upstream Github
at https://github.com/openexr/openexr/issues/130

Couple OpenEXR more tightly to ilmbase and require its exact .so
version.

Add UPDATING note, and bump PORTREVISION of all dependent ports.

Proto-STAGE hugin-devel, and mark it IGNORE because hugin is newer.

Approved by:	portmgr (implicit for bumping PORTREVISION on unstaged ports)