Improve test suite interface

ACID test functions in function `ACID`
External interface now gives the cell array of function handles
when argument is 0. This would allow to call such a function from
another test suite, i.e. to construct a test suite "everything"
that calls all other test suites.

In the output, it is documented better which test suite is ran.
Fix ACID(40): non-random data
Merge branch 'testsuites'