Use an offline first approach, where we prefer the cached version over
the network one.
This forces games using PWA to always re-export the project and not just
the PCK, so that the service worker version gets updated correctly, and
the end-user cache is correctly cleared on update.
With a very nice hack, a new hidden configuration option that delays
dropped files removal at exit.
This still leaks while the project manager is running, but will clear
memory as soon as it exits or load something.
(reminder, dropped files are reguarly removed after the signal is
emitted specifically to avoid leaks, but I prefer hacking the HTML5
config then the project manager).
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).
