[test] missing unittest.main() call in unittest_http_headers.py

[test] make unittest_webconfig independant of CWD if apphome is unset in ApptestConfiguration constructor, this later looks for a 'data' directory in CWD, making this test runnable only from web/test (and pytest do chdir before executing tests, so we did not noticed this problem).

[webctl] do not ask questions if verbosity is at 0 Closes #4641960.

[web] Slight tweak on jQueryUI's colors on links (related to #4564046) Follow up to commit 16f550b48d57 which was somewhat brutal. This change only overrides jQueryUI's CSS rules inside tab panes and leaves actual tab buttons alone.

[view] Remove unused imports

Remove obsolete __future__ imports Generators have been available since 2.3, "with" statements since 2.6.

[devtools] Remove unused local function Unused since cw's first commit.

[uihelper] Fix a possible NameError in meta_formconfig could occur when using FormConfig with a custom uicfg object. Closes #3802298.

[devtools] Avoid db_cache collisions and mis-loading This is done by stopping to share the db_cache between TestDataBaseHandler instances It may seem overkill, but is the only way I could get it to work properly. I think the whole db caching code needs some rework to better work with different db handlers. Closes #4601328

[devtools][pg] Remove a wrong assertion in _backup_database When using pre_setup_database, a repo gets initialised before calling backup_database. Hence self._repo is NOT None it that case.