Check if language is available and take "en" otherwise

[t-oster]

Hi,

I tried your version and was glad, that I didn't begin to translate it myself, what I was starting to do. But there was one little problem: My browser was set to "us" but your code doesn't contain "us" (eventhough you set it to default??).
However: This patch checks if the file exists before loading a language and loads "en" otherwise

[t-oster]

I also added the possibility to link to prefilled ticket-creation forms... so you can embed links in you page like http:https://ticketsystem/open.php?subject=Error&topic=MySampleDatabase

[jasperf]

Thanks a lot for this. I will merge this request. If Carlos bumps into any issues we can always reverse.

[jasperf]

@t-oster Thanks for the help!

[t-oster]

you're very welcome.