The SHOW DATABASES greatly slows down the test. By doing that only from
time to time, the test time drops from roughly 160 seconds to 15
seconds. There's also no point in continuing the test after a failure has
been seen.
Also added a missing sync_slaves to the database creation to make sure
they are created on all servers before the test starts.
See script directory for method. The script to run in the top level
MaxScale directory is called maxscale-uncrustify.sh, which uses
another script, list-src, from the same directory (so you need to set
your PATH). The uncrustify version was 0.66.
The tests failed to compile due to invalid use of try_query. For some
reason this wasn't detected by newer compilers.
Also fixed the compilation failure of mxs1713_lots_of_database on CentOS
7.
