Update to require and support orm_adapter >= 0.4.0

Credit: Rodrigo Rosenfeld Rosas (rosenfeld)
https://github.com/rosenfeld
Assist rbenv and rvm with .ruby-version

* orm_adapter requires 1.9.3 currently so this 
  should be okay.
Update LICENSE and README.md
History.txt -> CHANGELOG.md
Remove unneeded comments
Release Version 0.1.0