[threeten-dev] CaseInsensitive parsing

[Xueming Shen]

Here is the case insensitive version of the prefix tree.

http://cr.openjdk.java.net/~sherman/jdk8_threeten/radixtree_ci/RadixTreeCI.java

It holds performance relative good in -serve mode, about 2 x the case 
sensitive
version (it's 6 x in -client vm)

http://cr.openjdk.java.net/~sherman/jdk8_threeten/radixtree_ci/RadixTree.java

I do have a combined version, but it slows down the case sensitive 
version about 20%.
I'm not sure if we really case about this 20% in parsing.

-Sherman