Fixes #16 - time entry with start time ignored

1) Switched from the start endoing time_entries/start to the create end point time_entries. Start always used the current time and the create endpoint needs a start time specified.
2) This meant that the create_time_entry code needed to create a current time in the localized timezone as well as,
3) The parsed time argument to be put into a localized time string as well.

Much thanks to Margus at Toggl for pointing out the differences between the end points to me.
Updating last modified date