Added Error Logic to the TimeSheetService to make sure things get logged and fail when appropriate if a save cannot be completed.  Also added constraints to the ChargeLine object to allow for saturday - friday to be nullable.  Added a method to decrement the Assignment hours for a person when a TimeSheet is approved.
Merge remote-tracking branch 'mainRepo/master'

Conflicts:
	grails-app/services/com/greenumbrellasoftware/chronus/TimeSheetService.groovy
Added a lot of stuff