Edges with no event at top cannot be selected/do not show time

[bestchai]

Currently one can only interact with lines between two events. But, we should enable this interaction for lines that have no event at the start, and just count from 0 for the entire trace. So, it should be possible to select the edge above the first grey thread event below:

[Issue created by bestchai: 2016-08-04]
[Last updated on bitbucket: 2016-08-22]

[Comment created by bestchai: 2016-08-09]
The edge can be clicked, but it's not computing the right time value -- I'm only seeing 0 as the time delta for that edge. The value should be simply the time at which the event occurred (on the edge being clicked) relative to the very first event in the log

[Comment created by bestchai: 2016-08-09]
re-opening because time is not being computed properly

[Comment created by harjeetlalh: 2016-08-08]
This fixes issue #11 also handles the edge click.

→ <<cset 3539b5b>>

[Comment created by harjeetlalh: 2016-08-08]
Fixes issue #11

→ <<cset 3ec29b4>>

[Comment created by harjeetlalh: 2016-08-08]
Wait forgot to handle edge click.

[Comment created by harjeetlalh: 2016-08-22]
Fixes issue #11.

→ <<cset 97123ce>>