The change in each case is to call notmuch_query_create_with_syntax,
relying on the already inherited shared options. As a bonus we get
improved error handling from the new query creation API.
The remaining subcommand is 'tag', which is a bit trickier.
The files (test) scripts source (with builtin command `.`) provides
information which the scripts depend, and without the `source` to
succeed allowing script to continue may lead to dangerous situations
(e.g. rm -rf "${undefined_variable}"/*).
At the end of all source (.) lines construct ' || exit 1' was added;
In our case the script script will exit if it cannot find (or read) the
file to be sourced. Additionally script would also exits if the last
command of the sourced file exited nonzero.
