Use Y-m-d H:i:s date version format, so extension installers can notice newer FOF version on same day

When a component is released on the same day with a newer FOF version, FOF is not installed. This is because _installFOF() of the component can't check for hours/minutes/seconds. This is fixed by using Y-m-d H:i:s in stead of Y-m-d.
Merge pull request #204 from twentronix/feature/dateimprovement

Use Y-m-d H:i:s date version format, so extension installers can notice newer FOF version on same day