Change NO_ACT so it can be used in addition to other ignores

This results in a more flexible system and is less surprising as it means levels
can be used in the way they normally can in an ignore.

As an example the current approach to NO_ACT provides no way to let HILIGHTS
be shown, with this change /set activity_hide_targets can be recreated with:
  /ignore #channel NO_ACT
  /ignore #channel -except -regexp -pattern . NO_ACT HILIGHTS
(but obviously this can be configured in many more ways if desired).
Don't expand ALL when combined with NEVER/NO_ACT
Remove NO_ACT if we see a user specified hilight

In this path we can't look up ignores again because the print text signal
doesn't know the nick, etc. Instead just show it. The user can use -actcolor %n
or make the hilight more specific if desired.
Add NO_ACT checks for actions and notices
Add NO_ACT checks for DCC messages
Make /ignore -replies work with NO_ACT
Merge pull request #80 from dgl/noact

Change NO_ACT so it can be combined with other levels