is inconsistent
+ several improvements
Details:
- The subtest with assignment of floating point numbers to
  DECIMAL parameters in functions and procedures checks
  now that the final DECIMAL value is the same as if we assign
  the floating point numbers to columns, user variables etc.
  = The impact of math libs or truncation must be the same.
- Remove storage engine variants of this test because the
  stored procedure properties tested do not depend on
  the storage engine.
  Use the fastest storage engine (MEMORY) for any tables
  needed.
- reset global sort_buffer_size to startup value
- Partially improved formatting.