Revert "Merge pull request #268 from tkruse/avoid_valueOf"

This reverts commit 98da3808b1ac9b03b214a4f6274c7f95c2e0ba38, reversing
changes made to a9d3b3ae3fee5a1d92d6d5bab350cc313cf4f9a7.

I missed the change to "MetaClassImpl.java". This needs further review, therefore reverted the commit.