Adding 'Creation Date' to syntax.

Adding this to the syntax in support of some text-based inbox processing needs I have.  I have a running log of inbox items that looks like:

- 2013-09-01-2249 | INBX | [[GUIDE] ADB Workshop and Guide for everyone - xda-developers](http://forum.xda-developers.com/showthread.php?t=879701) 	
    > adb backup -f boot.img boot
- 2013-09-02-1623 | INBX | Make a sentiment analysis study that watches language over time and correlates w quant self ideas
- 2013-09-02-1623 | INBX | Lauren likes wide tea cups @done(2013-09-03-1010)
- 2013-09-02-1730 | INBX | Sync yelp and foursquare checkins (!)
- 2013-09-03-0747 | INBX | Shoelaces

I have a different script which runs down this text file and forces me to act on each item (archive, delete, or turn into omnifocus task -- for now, via otask), and I'd like to preserve the creation date because I'd like to, for example, analyze how long it takes me to complete a task from the moment it enters inbox.