[time.js] Added tests for time.Time.parse

Removed "minus" and "bce" fields from parser result since the parser only requires them for the
field "year". Since the parser result contains "year", this makes them kind of redundant and
uninteresting for the outside-world.

Change-Id: I49a618f4664b5c2eb5903ca8c4f88012ed29cb5a
Merge "[time.js] Added tests for time.Time.parse"