[HapProcessCeilometer] Accept timestamp without usec part.

Now we can accept both the following timestamp.

|  tate transition | 2014-09-09T23:38:09.926000 | state: alarm                                                         |
| state transition | 2014-09-09T23:48:10        | state: ok
Merge pull request #529 from project-hatohol/support-other-alarm-timestamp-pattern

[HapProcessCeilometer] Accept timestamp without usec part.