Testrunner: use amberc 'main' feature (fixes #620)
Merge pull request #701 from mkroehnert/testrunner

Testrunner: use amberc 'main' feature (fixes #620)
0.12.0 release preparations
Refactorings in amberc code
Migrate guide.
Spaces -> tabs
Merge pull request #703 from herby/amberc-refactorings

Refactorings in amberc code
clean checkout; correct -pre version set
update setversion.sh
Merge pull request #706 from mkroehnert/release

update setversion.sh
AmberCli: recategorize methods
Repl: allow identifiers whith one single character
Repl: change error handling to not print a complete stacktrace but only the error description (fixes #671)
Repl: recompile
- Adds Node >> isReferenced to avoid unneeded aliasing
- Better implementation of VariableNode >> isImmutable
- Adds IRASTTranslator >> visitOrAlias: and also alias inside BlockSequenceNode,
  fixing issue #704

- Recompiles all JS files
- Helios: Use the environment's doIt receiver for doIts.
Better formatting of Counter >> renderOn:
Merge branch 'master' of github.com:amber-smalltalk/amber
Merge pull request #708 from mkroehnert/cli

Update Repl to not print complete stacktraces on undefined variables
Speed up Helios reference browser