`amber init` runs `grunt`. Fixes #1009.
boot.js: formatting
boot.js: add package Kernel-Infrastructure where due
boot.js: shorter .initClass
boot.js: more robust "no subclass" detection in addClass machinery
boot.js: extract wireKlass
boot.js: copying to new array in readJSObject
boot.js: better "nil is subclass" message
Merge remote-tracking branch 'origin/master' into amber-init-recompiles
cli: Final message in `amber init`.
Merge pull request #1018 from herby/bootjs-small-fixes

boot.js small fixes
Merge pull request #1013 from herby/amber-init-recompiles

`amber init` runs `grunt`. Fixes #1009.
cli: Release version 0.12.0

First official amber-cli for 0.12.x line.