Make the parsing case insensitive

Optimized the pattern hash method to be case insensitive (to complete
the optimization of @mimmi20, pull request #8).
Optimized maximum execution time

When fetching the Browscap data in the Updater, sometimes a time out
could occur, so the option 'ScriptTimeLimit' has been added to
temporaily influence the maximum execution time (defaults to 300
seconds).