Often URL parameter keys contain characters which are not allowed in URIs, like square brackets. Those have to be escaped as well.

See http://adrianlang.de/ada/html-script-charset

includes unit tests. Extensions welcome.

Because ALT-GR fires a CTRL-ALT event on Windows systems, but ALT-GR is
needed to write square brackets on German Keyboards, CTRL-ALT can not be
used as modifier.

This patch introdues OS dependent modifiers. Mac systems continue to use
CTRL-ALT, all other systems use only ALT.

Let's hope this works out.

The keydown event can't be prevented in Opera (see
http://www.quirksmode.org/dom/events/keys.html) so this switches back to
keypress in Opera (keypress doesn't give the correct key codes in
Firefox). Furthermore Opera replaces '\n' by '\r\n' when inserting text,
thus the offset for cursor/selection placement was wrong.

addLogEntry()