Updated validators for requirement fields and added call to validate function.
Also improved logic for setting which fields are editable at each stage.

Contributors:
	David Modica
fix #38
fix #38
fix #39
change estimated and actual effort to int
Made a couple of small changes to logic flow and added onto a test.
Merge branch 'dev' into dev-feature-editmult
Some more work on updating estimates. It does not yet work correctly.
Appear to have finished updating estimates callback. One test passes, but I want to right a couple more before I'm sure.
Added another test. I'm now as sure as I can be that update estimates works. The recursive class is not as abstracted as I'd like it to be, and I'll look into pulling more into the callbacks later, but it works for the two functions Marty wants done at the moment (mass edits and updating estimates).