[Cin] New AppImage release with mostly only changes for Android/Termux builds

[Andrea paz]

@MatN
I don't remember if I used sudo with bld_prepare.sh; but since I was
following the instructions in the manual and Andrew's, I think I used
sudo (or su). However, as was mentioned in:
https://lists.cinelerra-gg.org/pipermail/cin/2021-October/003975.html
Some dependencies I had to install by hand.
But the problem is only with appimage, while compiling from git is always OK.