not to before submitted data directory.

Thanks to bartv2 for the heads up.

Only need to be three digits.

also show black background on links that are active, fixes the news app that doesnt show the bg for folders correctly

If datafolder is erased, the default value will be shown as a placeholder.

If installation is submitted without a datafolder the default value will be used.

Swap OC.dialogs.alert()'s parameters, so Error is shown
as its title.

Don't do _too_ much escapeHTML()

Also make long variables more readable by splitting them
up into shorter ones.

Also fix some CSS for Firefox.

A bit bugged though ...

 * escapeHTML(everything)
 * curly braces for if
 * camelcase function_to_call
 * add missing semicolae (?)

Fix #2557 and make the whole code more usable.

Two parameters for OC.dialogs.alert, otherwise one will be "undefined".

Also fixed missing translation.

CSS comments don't work like that.