the internal data dictiona
- re-enabled lowercase_table3 test;
- added a rule to throw away expected warning to mtr_report.pl;
- fixed a test case to produce unique warning.


mysql-test/lib/mtr_report.pl:
  Throw away a warning produced by BUG#29839 test.
mysql-test/r/lowercase_table3.result:
  Modified a test case to throw away expected warning.
mysql-test/t/disabled.def:
  Re-enabled lowercase_table3.test.
mysql-test/t/lowercase_table3.test:
  Modified a test case to throw away expected warning.