Currently we have many different places that convert String to UTF-8
bytes and back. We shouldn't maintain more code than necessary to
do this conversion and rather use Lucene's support for it.
This commit integrates the forbiddenAPI checks that checks
Java byte code against a list of "forbidden" API signatures.
The commit also contains the fixes of the current source code
that didn't pass the default API checks.
See https://code.google.com/p/forbidden-apis/ for details.
Closes#3059
