TagsPlugin: Mirror ticket tags into normalized `tags` db table, refs #4503, #9194 and #11096.

Parsing ticket fields per request has been a known performance hog, that's why
using the `tags` db table for regular access yields a considerable speed-up.

As a side-effect 'ticket' is the pilot for fixing a recently announced issue
with `get_tagged_resources` in the default tag provider implementation.
Nicely polished by stretching unit test coverage to this part of the code.

'''ToDo:''' `DefaultTagProvider` must be fixed as well, and other tag
providers should be reviewed too as a precaution.

git-svn-id: https://trac-hacks.org/svn@13165 7322e99d-02ea-0310-aa39-e9a107903beb
TagsPlugin: Cache `get_tagged_resources` for tickets, refs #4503.

Current implementation is for Trac >= 0.12, but likely a ''wontfix'' for 0.11,
if no code is contributed for getting it there, sorry.

git-svn-id: https://trac-hacks.org/svn@13166 7322e99d-02ea-0310-aa39-e9a107903beb
TagsPlugin: Some clean-up regarding usage of `set()` and set objects.

Part of this have been done and collected while reviewing surronding code.

git-svn-id: https://trac-hacks.org/svn@13167 7322e99d-02ea-0310-aa39-e9a107903beb
TagsPlugin: Tap into the potential of permission check short-cuts, refs #4503.

This has been based on the three years old  `lazy_permission_check.patch` by
otaku42, thanks a lot anyway.

git-svn-id: https://trac-hacks.org/svn@13168 7322e99d-02ea-0310-aa39-e9a107903beb
ThemeEnginePlugin [refs #11098] : Incorporate Apache(TM) Bloodhound theme's solution for template overrides ... [untested]


Version 2.2.0 release candidate 1

git-svn-id: https://trac-hacks.org/svn@13169 7322e99d-02ea-0310-aa39-e9a107903beb
ThemeEnginePlugin [refs #11098] : Fix typos in README - after [13169]

git-svn-id: https://trac-hacks.org/svn@13170 7322e99d-02ea-0310-aa39-e9a107903beb
TagsPlugin: Fix db setup for ticket tags unit tests, just like done for upgrade code before.

git-svn-id: https://trac-hacks.org/svn@13171 7322e99d-02ea-0310-aa39-e9a107903beb