Allow leading tabs in API fields

[jmathai]

To allow mobile apps to set a title automatically and still have the ability to reverse/rollback/etc we are allowing the \t to be part of the API fields.

Related issues

photo/mobile-ios#310
photo/mobile-android#441

[httpdispatch]

As for me better is to fix dateCreated timestamp issue. Then we will be able to generate title on the fly depend on user device locale. We've discussed dateCreated problem with @patricksan and my probposal for fix is like this:

If photo has exif date information save it parsed as timestamp in UTC timezone instead of GMT-7 like it is now. Then on device we can convert it to device specified timezone. So date will be always the same independently of user timezone settings. I mean if exif is 24.05.2013 10:00 then user will always see exact this information 24.05.2013 10:00 independently of timezone settings on device.

If photo doesn't have exif information when we need to take some parameter from device to save the timestamp. That timestamp should come already converted to UTC timezone from device. So it can be converted to any timezone in the future.

example:
we have photo with exif information like this:
24.05.2013 16:00
GMT+0 timestamp is 1369411200
but server stores it in GMT -7 which is 1369386000. In such case it is not possible to convert it back to 24.05.2013 16:00 on user device such as device doesn't know anything about server timezone offset GMT-7.
In case server will send information in GMT+0 on device side we can convert it to user timezone.
If my timezone is GMT+3 and i receive 1369411200 on device side i reduce 3 hours from it 3*3600 and will receive 24.05.2013 16:00 timestamp but in GMT+3 timezone

If we upload photo without exif, device should to send additional information in UTC timezone during upload. It can be file modification date.