Gruntfile: grouping non Dist jshint process

and setting it to check for scoped files
Git: adding temp dir to .gitignore
Src: introducing the scoped variable
Dump: using scoped variable in dump.js
Dump: reindenting dump.js
Core: scoping core.js and removing unused var
Core: externating core.js methods and objects
Core: calling Test object from scoped var
Diff: scoping diff.js
Equiv: scoping equiv.js
Equiv: whitespace
Equiv: moving vars declarations to top

plus minor code style fixes
Export: scoping export.js
Export: reindenting export.js
Test: scoping test.js
Test: export Test to the scoped object
Test: reindenting test.js
Assert: scoping assert.js
Assert: removing unnecessary variable
Assert: reindenting assert.js