some improvements

[to0oner]

The most important commit 88bd078 give the parser a big performance boost.

I've tested this with PHP 7.1.12 on some html files (size ~5kb), the parsing time decreases from ~4 seconds to under 0.1 seconds.

[robations]

LGTM — 88bd078 took a 2 min parsing operation down to 10 seconds in one test.

But RIP tburry/pquery :)

[robations]

Note there is some inconsistency between tabs and spaces within the source code, there is already inconsistency between files, but one line in the PR adds spaces into a file that has tabs.