Revert "AutoMode: Disable overriding rights of auto* capabilities."

This reverts commit 4a20270655aa898ce8fdd36c225056607645db46.
Add arguments ignoreChannelOp and ignoreDefaultAllow to ircdb.checkCapability.
AutoMode: Fix alternative capabilities handling.
Time: Make argument to @at optional. (Replacement for GH-533 that does not need nesting.)
Misc: Fix @version on Python 2.