Date and Time types and model functions

[tomhealey-icma]

To properly work with ISO date and time we need a low level time recordType. This will required low level changes to Rosetta DSL:

recordType time: hour int min int sec int msec int

recordType ISODateTime: date time offset

We also need functions to convert to and from ISODateTime:

func FormatISODateTime: inputs: date date (1..1) time time (1..1) offset int (1..1) formatType ISOFormatTypeEnum (0..1) output: isoDateTime string (1..1) set IsoDateTime: date->year + '-' + date->month + '-' +date-> day + 'T' + time->hour + ':' + time->min + ":" + time->sec + ":" + time->msec + "Z"

	...
	other formats 
	with UTC Offset : [+/-] offset

func ConvertISODateTime: inputs:
isoDateTimeStr string (1..1) output: isoDateTime ISODateTime (1..1)