qt: fix qtdbus build.

Fixes #19713.
qt: fix comment typo.
Allow requirements to specify a default formula.

This allows default resolution of requirements without user intervention.

Closes #19627.
rpm 5.4 (new formula)

Requires a patch to build with clang (no nested functions).
The ltmain.sh was broken due to a faulty Mandriva libtoolize.
Make sure that the OpenMP setting matches what beecrypt has.
Also ensure that all "mandatory" features are enabled.

Closes #12618.
Closes #12635.
Closes #19559.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>
Merge branch 'master' of http://github.com/mxcl/homebrew