svnwrap: remove dead code Some member functions of SubversionRepo were unused, and removing them frees other wrappers from adding possibly incorrect implementations of them. Two methods, `tags_at_rev' and `_get_copy_source' were completely unused and could easily be removed. Another two methods, `branches' and `tags' had explicit tests for them but weren't used in the code proper; they were removed too. The START property was unnecessary and could be removed with a tiny refactoring. No functionality change.

97f2079e3778511944ffb6a662520580650a3993 1.0
09c016174e332eceda015d3f43d96d7e0228acf3 1.0.1
4359ddd73b009fbb356c52ea5d99cba25222ee7a 1.1
8e621dbb82d4363a85317638ad237e2817c56347 1.1.1
093ae2915b452539b44390ee4ea14987484e1eee 1.1.2