Remove all command aliases ending in "instal" (single letter L) from the bash completion. This has the practical effect of removing the aliases "instal" and "uninstal" from bash completion, allowing "install" and "uninstall" to be auto completed once the first three characters of each "ins" or "uni" are typed in.
If the user has an alias overriding the `ls` command that modifies the
output (e.g. `alias ls='ls -F'`), it will cause unexpected characters to
appear in completions. Using `command ls` forces the shell to use the
command directly, without alias expansion.
This also blackholes the stderr of `ls` when used to avoid printing
errors during completion if the requisite directory does not exist.
