tizen-build.conf: added TZ_BUILD_TIME and TZ_BUILD_TS
Now, there are 3 datetime information in the file tizen-build.conf:
* TZ_BUILD_DATE: date and time UTC (example: 20141112_100948)
* TZ_BUILD_TIME: UTC time only (example: 10:09:48)
* TZ_BUILD_TS: timestamp = seconds since epoch (example:
1415786988)
Change-Id: Ic8a48b90507716f6a7737c76c3457dc7d92cec3a
Signed-off-by: Stephane Desneux <stephane.desneux@open.eurogiciel.org>