Added as an export option "Experimental Virtual Keyboard".
There is no zoom, so text/line edit must be in the top part of the
screen, or it will get hidden by the virtual keyboard.
UTF8/Latin-1 only (I think regular UTF-8 should work out of the box in
4.0 but I can't test it).
It uses an hidden textarea or input, based on the multiline variable,
and only gets activated if the device has a touchscreen.
This could cause problems on devices with both touchscreen and a real
keyboard (although input should still work in general with some minor
focus issues). I'm thinking of a system to detect the first physical
keystroke and disable it in case, but it might do more harm then good,
so it must be well thought.
This allow the loading bar to be much more reliable, even in cases where
realible stream loading status is not detectable (server-side
compression, chunked encoding).
This commit also removes the utils.js engine file, moving some of it's
content to config.js and some to engine.js .
(cherry picked from commit 018ee5a4dc)
