3861: Support setting blocks field in review requests the same way as depends_on field is set.

acsipak
What version are you running?

2.0.15

What's the URL of the page this enhancement relates to, if any?

http://adsrv2/reviewboard/r/<r>/

Describe the enhancement and the motivation for it.

Dependencies between review request are only editable on the blocked review requests' end (depends_on field). Dependencies should be editable from both ends.

What operating system are you using? What browser?

Windows 7 SP1
Firefox 37.0.2

Please provide any additional information below.