util: Add back GClass(String) constructor.
util: Comment out JDK 1.8-only Override.
util: Rollback GClass.baseClassName being cute and adding the package.

The assumption was that any simple name passed to baseClassName must
mean the class is in the same package.

But in real-world usage, it could also have meant that the simple name
was previously/separately imported as coming from a different package.
Merge branch 'master' into stable

* master:
  util: Rollback GClass.baseClassName being cute and adding the package.
  util: Comment out JDK 1.8-only Override.
  util: Add back GClass(String) constructor.