Added some very basic speed tests

- Created separate test class for speed tests, explicit only
  (will not run automatically with the rest)
- Currently only for insert and prepared insert
  (bug #1000515)
Merge pull request #64 from roji/bug1000515

Added some very basic speed tests

Created separate test class for speed tests, explicit only (will not run automatically with the rest)
Currently only for insert and prepared insert (bug #1000515)