can now do %info expansions in certain directives

only allowed for SourcePath ATM
this allows you to do things like defining a default source path like so:
-	DefaultSourcePath = git@github.com:%user/%project.git
which is sort of cool, if I do say so myself
allow overrides for Policy sections

projects can specify a ProjectPolicy directive
this will refer to a Policy section
values in that section (or in a git, svn, or cvs section _within_ that section) will override other values
-	although values specifically set in the project section still trump everything