Program manages the state and lifetime of the program object.

ProgramBinary holds the linked program and the code to do the linking.

There should be no functional change. WebGL conformance tests did not regress.
Review URL: https://codereview.appspot.com/6267047

git-svn-id: https://angleproject.googlecode.com/svn/trunk@1143 736b8ea6-26fd-11df-bfd4-992fa37f6226