Only install the catman page if catinstall is defined.  Noticed by tron@
Don't set GCC_REQD on Darwin, the gcc packages from pkgsrc do not work
due to missing critical functionality like -arch.

The build appears to work fine with the native gcc-4.2.1 on 10.8 anyway.
Changes 1.44.1:
* Parse option lines in the header section of include files using shell word
  splitting which allows quoting of multiple words and backslash-escaping of
  spaces.
Updated converters/help2man to 1.44.1
Add py-spf package.
Sender-Policy-Framework queries in Python.
Add mail/py-spf
Update HOMEPAGE.
Remove duplicate comment line.
Add devel/py-ipaddr
Google open source IPv4/IPv6 manipulation library in Python
Add devel/py-ipaddr 2.1.10
Fix typo.