Add an analyzer option to properly check ".call" methods.

Add an analyzer option to properly check ".call" methods.

Enabling this option fixes issue 21938.  For now the option is
disabled by default, since there is a lot of code in the dart SDK (and
in third_party) that isn't warning clean with this option enabled.
Once the SDK and third_party code have been cleaned up, we should be
able to turn this option on permanently.

BUG=dartbug.com/21938
R=scheglov@google.com

Committed: https://code.google.com/p/dart/source/detail?r=44390

[Paul Berry, 2015-03-11 00:18:10]

paulberry@google.com changed reviewers:
+ scheglov@google.com

[scheglov, 2015-03-11 00:22:31]

LGTM

[Paul Berry, 2015-03-11 00:35:45]

Committed patchset #1 (id:1) manually as 44390 (presubmit successful).