Improve test run change notification email

[okainov]

Right now there are email notifications being sent after test run change, but they don't really contain important info what exactly was updated.

Test run 8 has been updated for you.

Links

Test run: XXXrun/8/

Basic run information

Summary: XXX
Managed: XXX.
Default tester: XXX.
Product: XXX
Product version: XXX
Build: XXX
Estimated time: 0:00:00
Notes:

Test plan information

Test Plan: XXX

Actual change was in setting "Finished" to True and this is not displayed at all in the email. I would expect having only changes in email, but not all test run details

[atodorov]

See my comment on #216. Unfortunately we don't have the internal machinery to easily make the distinction what has been changed. I'll keep researching on this topic since it is a good feature request.