Trie Data Structure

[Michael Truog]

Hi,

I implemented a trie data structure that has performed 20% faster lookups
than the dict implementation in R14B01.  I have tested the code but it can
always benefit from more testing.  The trie module provides the same
interface as the dict module, but requires a list of integers for the key.
Please tell me if you find issues in the code.

Code:
https://github.com/okeuday/CloudI/blob/master/src/lib/cloud_stdlib/src/trie.erl

Blog posts:
http://okeuday.livejournal.com/16454.html
http://okeuday.livejournal.com/16182.html (dict as the fastest general tree
data structure)

I know you can use ETS for similar problems, but avoiding shared data helps
utilize Erlang's scalability advantages.

Thanks,
Michael Truog