Added a non-alphanumeric filter, length filter, and stop word filter
Moved filters to their own package
Fixed an issue where the regular expression for removing non-alphanumeric characters was broken.
Moved a number of filters to the transform package as it better fits theri function.\n\nAdded a basic sorted map implementation (it will change) and a similarity package (which is also likely to change)
Updated import path due to move to mirgit
Added a sentence tokenizer
Added distance measure. TweetTokenizer now converts 1-9 to their word form (e.g 1->ONE). SentenceTokenizer will not split on a comma if told to.
Fixed a stay function in lowercase filter