Some changes in the TitleHelper to solve performance issues.

 * local caching of resource values
 * removeing a check if resultset has no entries
 * important change for models / resources without label information

BugFix of TitleHelper to fix the key check in query results array

BugFix of TitleHelper to fix the key check in query results array (damn again)
Merge pull request #195 from AKSW/feature-titlehelper-fixes

Some changes in the TitleHelper to solve performance issues.