Include javadoc comments on package declarations

The java standard allows for javadoc comments, in addition to annotations,
before the package identifier in the file package-info.java.

http://docs.oracle.com/javase/specs/jls/se7/html/jls-7.html#jls-7.4

This commit looks for javadoc in addition to annotations preceding the
package declaration, however it does not limit the search to just files
name package-info.java.