* Rewrote convertArray() as an RD parser (with inline tokenizer) as suggested on CR r60986. Fixes unclosed rule issue (with parser test). Fixes O(N^2) timing.
* Removed $this->mMarkup abstraction. Life is complicated enough as it is.
* Replaced a couple of instances of explode() with StringUtils::explode(), limited element count in a couple more.
In ConverterRule:
* Removed mConvTable initialisation from the constructor, unnecessary
* Optimised the "-{xxx}-" tight loop by replacing function calls such as count() and in_array() with language constructs such as isset(). Reduced execution time from 356us to 275us.
* Cached $varsep_pattern for further reduction to 243us.
* A couple more parseFlags() hacks brings it back to 230us.
* Split out $this->mVariantFlags from $this->mFlags. Rearranged flag detection into a foreach/switch to avoid unnecessary isset() calls. 189us.
* Added a special-case optimisation to generateConvTable() for the case where there are no tables defined inline in the article. 116us.
* Fixed bug from r37499: "!R || !N" is always true since they are mutually exclusive, "!R && !N" was intended (with parser test).
* Fixed E_NOTICE from "-{N|foo}-"
