Can show and set tagopt

By @ch3cooli on November 18, 2012 16:01 (imported from Google Code)

---

Fetch dialog default fetch tag behaviour is controlled by remote.xxx.tagopt.
It is clearer to tell user the behaviour of fetch if nither --no-tags or --tags are specified (checkbox intermediate state), it will fallback to config remote.xxx.tagopt.
If config not specified, then the behaviour is to fetch tags that are reachable from remote HEAD.

Sometimes, we want to set a remote that never fetches tags from, for example, working on an independent fork where the version numbers are not compatible with the original project.
I suggest to add tagopt settings in settings remote page.