Deprecate items field in ParameterSchema.
Add unit test in restli-client to cover the param() and reqParam() functions.
Add integration test to cover the deprecated items field for backwards compatibility.
Add integration test in restli-int-test.
Fix bug that ArgumentBuilder can't handle array of complex type.
Update build script for the deprecation.
Update publishIdl.gradle to handle case when no idl is found.
Use Gradle 1.5.

RB=126830
R=mtagle,dyoung,sihde,adubman,jbetz,slim,si-dev
A=jbetz,slim
Addjust CHANGELOG.