Supporting a trailing comma in NM_MAKE_STRV() can be desirable, because it
allows to extend the code with less noise in the diff.
Now, there may or may not be a trailing comma at the end.
There is a downside to this: the following no longer work:
const char *const v1[] = NM_MAKE_STRV ("a", "b");
const char *const v2[3] = NM_MAKE_STRV ("a", "b");
but then, above can be written more simply already as:
const char *const v1[] = { "a", "b", NULL };
const char *const v2[3] = { "a", "b" };
so the fact that the macro won't work in that case may be preferable,
because it forces you to use the already existing better variant.
"shared/nm-utils" is a loose collection of utility functions.
There is a certain aim that they can be used independently.
However, they also rely on each other.
Add a test that we can build a minimal shared library with
these tools, independent of libnm-core.
