allowing customized year parsing
Refactored accessor methods
Use deprecate for global export deprecation

It looks like this in the root Node.js scope is NOT the global scope. So
rename global -> global_scope and fall back to 'global' in case it exists.
Fix addOrSubtract to properly handle updateOffset
Add logic in zone to handle impossible keepTime-s
Fix startOf issues across DST with updateOffset
Make jshint happy
fixing jshint errors
Make sure no Date constructor is used in tests
Fix iso parsing with more than 3 subsecond digits
Merge pull request #1578 from ichernev/fix-iso-times

@changelog
@section bugfix
@description Fix iso parsing with more than 3 subsecond digits
Merge pull request #1577 from ichernev/extract-date-constructor

Make sure no Date constructor is used in tests
Merge pull request #1545 from icambron/abstracted-year-parsing

Allow customized two-digit-year parsing
Merge pull request #1564 from ichernev/fix-zone-madness

@changelog
@section bugfix
@description Simplify zone handling