Revert r41544 "Update dart binaries used for running tests to version 1.7.2"

Also revert fixes for test scripts for this update, r41546

BUG=
R=ricow@google.com

Review URL: https://codereview.chromium.org//708733003

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41547 260f80e4-7a28-3924-810f-c04153c831b5
Update documentation for RandomAccessFile

R=kustermann@google.com, lrn@google.com
BUG=http://dartbug.com/21516

Review URL: https://codereview.chromium.org//702363002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41548 260f80e4-7a28-3924-810f-c04153c831b5
Mark test failing due to dartbug.com/21523

Review URL: https://codereview.chromium.org//706883002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41549 260f80e4-7a28-3924-810f-c04153c831b5
Encode super calls via extra properties on prototypes.

BUG=
R=floitsch@google.com, sra@google.com

Review URL: https://codereview.chromium.org//693883003

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41550 260f80e4-7a28-3924-810f-c04153c831b5
Fix type warning in dart:async.

Review URL: https://codereview.chromium.org//705963002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41551 260f80e4-7a28-3924-810f-c04153c831b5
Revert "Mark test failing due to dartbug.com/21523"

Fixing a type-warning also fixed this problem.

Review URL: https://codereview.chromium.org//709443003

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41552 260f80e4-7a28-3924-810f-c04153c831b5
Fix hanging test script batch runners.

BUG=
R=ricow@google.com

Review URL: https://codereview.chromium.org//707733003

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41553 260f80e4-7a28-3924-810f-c04153c831b5