TestSuiteRunner uses fork; impl. fork using pool.
Fix: no local return in async block.
pure NodeJS based version of amberc
BlockClosure >> ensure: impl'd by try/finally.
Kernel-Objects: change thisContext -> smalltalk.getThisContext() in js files
repl: fix Makefile (specified libraries are already included)
repl: recompile
Simplified TestRunner >> performFailure:
Merge pull request #273 from herby/ensure-is-finally

BlockClosure >> ensure: impl'd by try/finally.
Merge pull request #274 from herby/performfailure-call-runcase

Simplified TestRunner >> performFailure:
Merge pull request #272 from herby/uiless-testrunner

TestSuiteRunner uses fork; impl. fork using pool.
Fixed ensure semantics and accompanied test.
amberc.js: use same set of compiler libs than amberc
JS reserved word `boolean` clash in boot.js
server.js: boolean is reserved word in JS
amberc.js: writing of .js files is now async
amberc.js: checking of closure.jar is now async
repl: boolean is reserved keyword in JS
server: fix shadowed port variable
amberc.js: move amber_dir and smalltalk to defaults object