Special Examples TCs

Examples which make a special use of STKUnit:
* test_checkup
* test_lint
* test_security

These TCs are invoked by a TS called diagnostix.

They are just examples of a special use of STK/Unit, but could possibly evolve over time and become useful tools.

TEST_CHECKUP
is a TC which generate fails for problems which come up with db usage:
* big fragmented tables
* empty databases
* non-MEMORY empty tables
* past events
* unused 3rd party SE
* bad configuration
...

TEST_LINT
is a TC which checks the structure of SQL objects searching for bad practices:
* tables with no primary key
* long PK
* FK between different types
* UNSIGNED AUTO_INCREMENT
* redundant index on InnoDB (ie: (name,pk) ad (name))
...
and one pass for all objects which have no problems.

TEST_SECURITY
* users with no rights
* rights on non-existent objects
...