DateAndTime corrections
- fix typo in setFraction which caused fractional seconds which were all zeroes to be not supported
- add proper handling of time zones to the before method
- fix GMT timezone names in the toCalendar method
- change the toCalendar method to correctly use Calendar.HOUR_OF_DAY (24 hour) instead of Calendar.HOUR (12 hour) to set the hours
- add fractional second support to the toCalendar method (previously not implemented)
- fix the time zone handling for the now method
- fix the class so that it supports negative offsets of less than an hour

git-svn-id: http://gforge.hl7.org/svn/fhir/trunk/build@2956 2f0db536-2c49-4257-a3fa-e771ed206c19