Merge pull request #5 from amplify-education/regex_fix

Escape backslashes in js string so they are part of RegEx
Key bugs using a 32-bit signed int calculated using Java's fast String.hashCode

Code was taken from a response on StackOverflow:
http://stackoverflow.com/questions/7616461/generate-a-hash-from-string-in-javascript-jquery

This made indexing on a macbook ~20x faster.