Small fixes in the translation tool

This morning I did some small improvements in the aprs.fi translation tool. It now gives some feedback when buttons are pressed (like "Saved changes!"). It works better with strings containing " and ' characters (there was a little escaping bug in the HTML generation). It shows string-specific descriptions and translation hints (which have existed for quite a while for some strings). It also cleans up some extra whitespace from the translated strings, and uses a multi-line editing text box for strings longer than 90 characters.