Code clean-up, add utility class for incremental scanning, add tests

R=scheglov@google.com

Review URL: https://codereview.chromium.org//742013003

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41855 260f80e4-7a28-3924-810f-c04153c831b5
Move incremental scanner to separate file

R=scheglov@google.com

Review URL: https://codereview.chromium.org//746503002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41856 260f80e4-7a28-3924-810f-c04153c831b5
Update 'nameOffset' for elements during incremental analysis.

R=brianwilkerson@google.com
BUG=

Review URL: https://codereview.chromium.org//742103003

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41857 260f80e4-7a28-3924-810f-c04153c831b5
Provision the editor samples by downloading them from github.

R=danrubel@google.com

Review URL: https://codereview.chromium.org//743693003

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41858 260f80e4-7a28-3924-810f-c04153c831b5
Remove in-bodies analysis from DeclarationMatcher.

R=brianwilkerson@google.com
BUG=

Review URL: https://codereview.chromium.org//741183002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41859 260f80e4-7a28-3924-810f-c04153c831b5