Nathan Woodrow c467e79f3c Add expression functions for handling date/time:
- year,month,day,hour,minute,second extraction
    - new QgsInterval objects - handles time amounts
    - age() function returns the difference between two  datetimes
    - $now returns the current date and time
    - support for datetime - interval = new datetime
    - tointerval, todate, totime functions
    - tests ;)
2012-06-30 20:40:54 +10:00
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2010-08-28 22:35:41 +00:00
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2012-04-22 01:40:14 +02:00
2011-11-20 13:43:21 +01:00