graphics/cairo: prepare for autoconf 2.71
- configure.ac contains GTK_DOC_CHECK and the new autoreconf runs
gtkdocize in that case so add a build dependency.
- fix post-patch commands that patch files which are regenerated by
- remove old patches while here.
The MAP_NORESERVE flag to mmap() has never been implemented in FreeBSD and
is being removed. No portrev bump needed since the kernel will continue to
accept this flag for old binaries even after support for it in new binaries
Approved by: portmgr (antoine)