Iconic changes

Fixes up various icon issues:
+ Attempts to unify "page" theme for Editor controls and normal TreeWidget icons.
+ Corrects some (resource) file name problems
+ Uses QStringLiteral() wrapper for all icon file names (as they are all read-only, non-translatable QStrings)
+ Recodes Main Toolbar and TreeWidget Icon setting size coding so that global changes get propagated to ALL profile editors.

+ Also picks up some of AhmedCharles's modifications in passing.