Let Rocket handle it's own background thread

Let Rocket start up it's own background thread itself, instead of creating
a thread to run it in ourselves. This way we can just start() it on plugin
activation and stop() it on plugin deactivation, making the logic much
simpler.
Merge pull request #158 from zoni/rocket_handle_own_thread

Let Rocket handle it's own background thread
Fix "irc" module naming conflict with python-2.7.

Using "from irc import ..." in module named "irc" causes python-2.7 to
try to re-use __module__ in that import, and not look it up in sys.path.

Fix is to force such lookup via "imp.find_module".
Any ImportError (either missing "imp" or other "irc" modules) should be
treated same as before, causing a fatal error.
Use password (as PASS) in irc backend.

Was silently discarded previously.
Add HIDE_RESTRICTED_ACCESS option to supress access errors.

Use-case is restricted-access bots in populated channels, so that bot A
may ignore "!cmd" message from user M (intended for another bot or user)
without polluting channel with error messages.
Strip XHTML/XML formatting in all irc messages.
Use https for all github repos.
Merge pull request #164 from mk-fg/use_https_repo_urls

Use https for all github repos.
Merge pull request #163 from mk-fg/irc_strip_xhtml

Strip XHTML/XML formatting in all irc messages.
Merge pull request #162 from mk-fg/access_ignore

Add HIDE_RESTRICTED_ACCESS option to supress access errors.
Merge pull request #161 from mk-fg/use_irc_password

Use password (as PASS) in irc backend
better logging
reput the empty command test before testing security about it
Revert "Fix "irc" module naming conflict with python-2.7."

This reverts commit 63bf277df1949875490eec0f08294fa67609de57.
forces absolute imports to align python 3 and python 2 behavior
Merge branch 'pr/160'