jquery-tabby is never used

If used, .tabby() should be called on some jquery expression,
but 'tabby' substring is never to be found in the code.

Maybe it was used in past, but now CodeMirror takes care of Tab fine.
Merge branch 'master' into tabby-out
Merge branch 'master' into tabby-out

Conflicts:
	config.js
Merge branch 'master' into tabby-out
Much faster asJavaScriptSelector

IOW, much faster test runner in Helios.
SmalltalkImage >> at:ifAbsent: made consistent with at:[put:]
Class >> heliosClass. Fixes #1025.
Remove `amber test` command. Fixes #996.
Recompile.
Enclose exec'd files into double quotes. Fixes #1044.
amber-cli: Release version 0;12.3. Bugfix release.
Merge pull request #1047 from herby/tabby-out

jquery-tabby is never used
Merge pull request #1050 from herby/faster-dnu

Much faster asJavaScriptSelector
Regression test for #1062.
Merge branch 'regression-1062' into bootjs-dnu-refactor

Conflicts:
	src/Kernel-Tests.js
	src/Kernel-Tests.st