It could happen that the child sources were disabled, but when they
were claimed again they were not enabled, which made them hidden
for a user.

The former calls the later internally, but apart of it it does few
useful things too, like removing the disk file, thus it is not
used the next start again.

It could place locale files into $PREFIX/locale, instead of $PREFIX/share/locale.
The change follows bug 703732.

It could happen that the test program failed due to missing CFLAGS
or even LIBS, thus it could give incorrect results.

Since this change the client is responsible to provide credentials
to use to authenticate backends (through ESource-s, to be more precise),
unless the credentials are already saved.