At startup Termux now checks if there is external storage available,
and creates a private area on the external storage if one exists as
well as creating a symlink to the private are at $HOME/storage.
The Termux implementation of the ${CSI}${N}T escape sequence to scroll
down N lines (SD - Pan Up) did not take the top margin into account
when figuring out where to place the scrolled rows.
Fixes#28.
When mouse reporting is enabled, do not send mouse events on up
after a long press, since that causes e.g. the cursor to move in
vim when lifting the finger after long pressing for the menu.
Starting with Android 6.0 the system may automatically backup app
data when a users installs an app on a new device or reinstalls an
app on one. After this commit this only affects the $HOME/backup/
folder, so that the user may choose what to backup.
See https://developer.android.com/training/backup/autosyncapi.html
If the activity had been destroyed waiting for the installation to
finish the code would crash trying to display welcome dialogs (on
success) or error dialogs (on error).
