Even empty QRegExp can occupy a lot of space in memory, which can
grow into a big number with tens of thousands AdBlock rules.
QRegExp is now allocated with new, and only when really needed.
- improved performance with not using regexps when not necessary
- added support for element hiding even with domain restrictions
- almost all types of rules are supported now
* exceptions are only some special cases when rule has
unssuported options (part of rule after $ character)
* those rules are ignored
- you can add subscriptions in AdBlock dialog or with
abp: scheme links
- however, AdBlock rules are not yet optimized for performance
so you shouldn't add too much subscriptions
performance optimizations will come in next commits
- support for element hiding is still yet to come too
closes#266