Support for ActionSubstitutorFactories.

Change-Id: I06b391f62bf6e72b0f24d2dda91e36242564fdff
Depends-On: Ie2960171e29fa4069747ca9a6cd8b427ffc73003
Reviewed-on: http://gerrit.dmdirc.com/2910
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Greg Holmes <greg@dmdirc.com>
Don't use deprecated ctor.

Change-Id: I50ebe298668913a1fdfcbffacc24e20bd45a3bf2
Reviewed-on: http://gerrit.dmdirc.com/2911
Reviewed-by: Greg Holmes <greg@dmdirc.com>
Automatic-Compile: DMDirc Build Manager