improved search performance for large documents

[siggemannen]

I noticed that for large documents, there was a noticeable delay when there are a lot of hits and marking occurences is ON and you do a search. Made some improvements to the SearchEngine by keeping track of index window when searching and advancing instead of creating new strings.

Went from 10 seconds on a 3mb file to sub second results. Unfortunately replaceAll is still slow but will do it next!

[coveralls]

Coverage decreased (-0.09%) to 64.538% when pulling 482ae8890a714e6ff5705e8483907416f9cf0d71 on siggemannen:master into 3ac9c65144a3ae1d01785c4a75f562f20f496f58 on bobbylight:master.

[siggemannen]

I think i got the coverage up a bit, and merged the fixes from main, but now it seem to fail due to length of a class i haven't changed! @bobbylight , is there "hope" for this patch or do i need to do something else, this is my first patch, so i'm probably doing something wrong :)

[bobbylight]

Don't worry about the CheckStyle error about RSyntaxTextArea.java being too long - I did that; I'm pretty bad about doing a clean build before pushing and sometimes push with checkstyle failures (I know I have it configured to be pretty strict, even for myself :)).

I want to noodle over this patch before accepting it - it makes some decent changes to the search engine and I want to make sure I comprehend it all and understand the ramifications before merging it. Unfortunately I've been pretty busy lately so it's taking me a little bit to get to this.