Update command lists to latest for each repository

Uses commits:

termux-packages https://github.com/termux/termux-packages/tree/7337720
game-packages https://github.com/termux/game-packages/tree/3dcb88d
science-packages https://github.com/termux/science-packages/tree/ed28bce
termux-root-packages https://github.com/termux/termux-root-packages/tree/21e6481
unstable-packages https://github.com/termux/unstable-packages/tree/b779f2a
x11-packages https://github.com/termux/x11-packages/tree/c578742

Special release for Android 5/6 packages

1.42.1

initialize android-5 branch

Fix install location of command-not-found

Change so that command-not-found is installed to $PREFIX/libexec/termux instead of $PREFIX/bin

Missing install instruction added

An install instruction was added to the CMakeLists.txt.

Support for multiple repos

Command-not-found has been rewritten in c++ and can now handle multiple repos. Suggestions are shown in this format:

No command shark found, did you mean:
 Command shar in package sharutils
 Command tshark in package tshark from the root-repo repository
 Command sharkd in package wireshark-gtk from the x11-repo repository