* .gitignore | adding unicode.js file to the build script | trim() in run-tests script | * travesre
core: avoiding label being interpreted as variable | * core.__getNodeBegin
loopClosures update: remove restrictions, improve resulting code

* tests
letConst: ability to mark variable node to force transpiler to rename this variable

+ markForRenaming
+ isMarkedForRenaming
+ note about let/const in global scope