Base Employee Change + FullTime Finished

Base Employee changes include
- Check methods does field validation
- Validate methods check for valid object validation
FullTime changes include
- SetDOH and SetDOT would will accept any valid date; it wouldnt care if
dob or doh is already set/null or not so that the order in which
validateDOT or validateDOH get called doesnt matter
- But Validate will return false if they are null or if their range
doesnt match
Fix bugs to make the solution buildable