- Use binary charset in acl_cache, to make searches case sensitive
 - Add testcase 


mysql-test/r/grant2.result:
  Update test result
mysql-test/t/grant2.test:
  Add test case for bug#17279, checking that user with access to TESTDB can't create TEStdb
sql/sql_acl.cc:
  Use binary charset for the acl_cache to make the hash lookups case sensitive.
  Thus denying user with access to "TESTDB" access to "TEStdb"