Merge pull request #16 from apoorv2404/master

Subscript Handler Updated
Test
Merge remote-tracking branch 'upstream/master'
Input Message Fixes
Various Fixes
self support
self support
Expression Attributes fixed
Minor Fixes
Lib Reduction + Str Implemented
Delete range.dart
Delete input.dart
Lib Fix
XRange and Lib Fixes
Operator Addition + Code Reduction
Str Escaping Fixes
Minor Bug Fixes
Sprintf Lib Implemented
Seemingly Shady Global Scope Implemented
Escaped $ in string