When running the test suite without building first, it is desirable to
have the tests consider these variables being undefined as equivalent
to the feature not being present, and in particular for the tests not
to generate errors.
Unify the subtests by requiring test_begin_subtest before
test_expect_success. (Similar change for test_expect_code will
follow.)
This increases clarity in the test scripts by having a separate line
for the start of the subtest with the heading, and makes it possible
to simplify the test infrastructure by making all subtests similar.
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.
In the case the these tests fail, they generate a bunch of output;
this output is not very interesting because it is just the successful
output of a man page. It does however make it hard to see what tests are actually failing, even with NOTMUCH_TEST_QUIET
All test scripts to be executed are now named as T\d\d\d-name.sh,
numers in increments of 10.
This eases adding new tests and developers to see which are test scripts
that are executed by test suite and in which order.
