During the FreeNAS build, this command will be
executed:
    /usr/local/bin/git svn find-rev

If you have devel/git, and not devel/git-subversion installed,
this command will fail.

Update the README to include the right port to install.
When invoking do_build.sh, if user specifies GIT_REPO or GIT_PORTS_REPO,
then use the value of those variables.
If those variables are set, do not print out warning message that
local repo is not specified.
Merge branch 'master' of git://github.com/rodrigc/freenas into rodrigc-master