Add --branch option to wescamp so we don't have to infer this from the wescamp checkout path

git-svn-id: http://svn.gna.org/svn/wesnoth/trunk@56303 75b3775d-3801-0410-9e12-e2e43121521d
Use --branch to determine addon server port if not specified

git-svn-id: http://svn.gna.org/svn/wesnoth/trunk@56304 75b3775d-3801-0410-9e12-e2e43121521d
Check for the configuration we need and only the configuration we actually need

git-svn-id: http://svn.gna.org/svn/wesnoth/trunk@56305 75b3775d-3801-0410-9e12-e2e43121521d
Add an --error-log option to wescamp.py, which writes warnings and errors to a specified file

git-svn-id: http://svn.gna.org/svn/wesnoth/trunk@56306 75b3775d-3801-0410-9e12-e2e43121521d