Doing the directory permission checks after all the values have been set
helps avoid problems with intermediate values that aren't valid. This
happens when --basedir generates invalid derived paths and the correct path
is provided as an argument right after it.
The path parameter is read from the configuration file only if it hasn't
been modified by a command line option. The case where an invalid command
line option is given but a valid configuration parameter would override it
is still treated as an error.
Also added a clarifying comment into set_dirs to make sure the handling
for the two path parameters is not moved inside set_runtime_dirs.
Fixed the testing scripts for the REST API and MaxCtrl now that the
directory permission checks are done correctly. Previously some paths seem
to have been ignored.
Moved and renamed the starting and stopping scripts from the REST API
tests to a common directory. This way the MaxCtrl tests can use the same
scripts to start and stop MaxScale.
Also moved the test configuration file into the `test/` directory and
changed some of the default directory locations.
