Autotext Improvements and patricia tries adition

Hello, Not sure where to start..

This  is first commit about language related improvements. I love the customization options this keyboard provides, but the language features had some limitations, I would like to work into this, because I wish to have a great word dictionary/prediction/suggestion/etc.

This commit, improves AutoText feature, and there is room for more.

* Custom tries where replaced with https://code.google.com/p/concurrent-trees/ , because the previous version was having some size limitations, and also was missing some words, concurrent-trees is a robust solution, full featured.
* Generated trees are cached to disk in serialized forms (if available) /data/AnySoftKeyboard/AutoText ( example /data/AnySoftKeyboard/AutoText/en.serialized )
* Trees are generated in background, and will become available when these are processed.

TODO:

* when the application/service loads (starts), it should load to memory the most used generated trees.
* tree generation and serialization should be performed on add-on installation and not the first time you load open the keyboard/switch dictionaries.

Improvements over previous version:

* better and robust handling of words in trees
* no size limits
* faster loading and switching (specially with big auto-text files)
* tree caching

I still need to investigate how the other parts related to language works..