Improved code and solved #3

Changed code to match
[bluMyst](http://www.reddit.com/r/ProgrammerHumor/comments/1w59yt/a_userscript_that_injects_political_correctness/cezw9zf)
suggestion and solved #3.
Now all script settings are next to head, for easy editing, and is made
only from strings. Regular expressions are created separately, fixing
issues with replacements inside words or starting, or ending, text
nodes.
Merge pull request #4 from qgustavor/master

Improved code and solved #3