Fix most getIconManager() calls.

Change-Id: I8070f50bf1e22459f8a33bdc88bb64ec95c4b021
Depends-On: Id672fec154a19c999b078b3980681937f62bfb41
Reviewed-on: http://gerrit.dmdirc.com/2841
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Greg Holmes <greg@dmdirc.com>