Cache global config files
Whenever we read a config file, we are first parsing kdeglobalsrc. This caches the parsed entries so that they can be reused as long as it hasn't changed.
This reduces the parseConfig calls (which is mostly prominent at early process startup) from 18 to 12 (33%) ksmserver-logout-greeter. This also means there's better cache locality as well as less memory allocated as a lot of objects are shared but I have not measured this.
I'm pretty sure I already submitted something along these lines in phabricator times. I think that time I didn't do the cache invalidating business and we never got this merged.