Remove Experimental warning from package-info files

[GoogleCodeExporter]

Remove the following experimental warning from package-info.java files
 * <p>
 * <b>Warning: this package is experimental, and its content may be changed in incompatible ways or
 * possibly entirely removed in a future version of the library</b>
 * </p>
Those packages aren't experimental any more.

DON'T CHANGE package-info.java files if the package is annotated with 
@Experimental as following:
{@link com.google.api.client.util.Experimental} <br/>
Those are real experimental packages.

The same work should be done also on oauth and api projects

Original issue reported on code.google.com by pele...@google.com on 13 Mar 2013 at 2:55

[GoogleCodeExporter]

https://codereview.appspot.com/7786044/

Original comment by yan...@google.com on 21 Mar 2013 at 8:36

• Changed state: Started

[GoogleCodeExporter]

Original comment by yan...@google.com on 27 Mar 2013 at 4:14

• Changed state: Fixed