Fixed file encoding issue.
Added support for the NOT_NULL constraint.
Added javadoc on constraints.
Added tests for invalid contracts.
Added jar and source jar in the download folder
Update README.md
Update README.md
Updated to 1.6.0
Merge branch 'feature-batch' of github.com:Shusshu/ProviGen into feature-batch

Conflicts:
	ProviGen/src/com/tjeannin/provigen/ProviGenProvider.java