PR merge policy

[Vlad Rozov]

Lately there were few instances where PR open against apex-core and 
apex-malhar were merged just few hours after it being open and JIRA 
being raised without giving chance for other contributors to review and 
comment. I'd suggest that we stop such practice no matter how trivial 
those changes are. This equally applies to documentation. In a rear 
cases where PR is urgent (for example one that fixes compilation error), 
I'd suggest that a committer who plans to merge the PR sends an explicit 
notification to dev@apex and gives others a reasonable time to respond.

Thank you,
Vlad