Files are now quoted with ' instead of " now as to avoid more edge cases
that come from using quotation marks. Now only ' have to be escaped in
the item paths.
Sometimes empty elements containing only spaces are pushed in to the
packages array, before the code would only detect that there are no
pacakges to install when only one spaces was inserted, now it should
work for any arbitrary count of elements containing only spaces.
Adding the -r argument to xargs makes it not run for no reason when
there are no packages to trim spaces from. Otherwise it'd always run at
least once and sometimes misbehave.
Using the ogg container allows to also embed cover images while still
using the opus codec.
Also fixed an edge case that would make the script fail if the first
thing it iterated on was a regular file which didn't require conversion
if the parent directory wasn't already created.
