perf(makeDateFromInput): no need to match regex if input is a Date

The moment constructor when passed a Date should be the fastest. There is
no need to match the aspNetJsonRegex before testing if the `input` is a
Date.
style: declare var at top
Runt grunt tests for jbrockmeyer's comit for Issue 1715
Merge pull request #1716 from jbrockmeyer/getRelativeTimeThreshold_Issue_1715

Fix issue #1715 to retrieve relativeTimeThreshold settings

@changelog
@section features
@description Allow getting relativeTimeThreshold
Implement accurate moment.duration({from, to})
Better bubbling of days to years in duration
Use duration object in relativeTime
internal relativeTime now accepts only duration object
Fix bugs in humanize and asYears
Fix moment tests
Fix language tests
Fix korean test label
Merge pull request #1642 from ichernev/fix-humanize

Fix humanize

@changelog
@section bugfix
@description use duration object for relative duration strings
@breaking relativeTimeThreshold keys are now changed to 's', 'm', 'h', 'd' and 'M'. Also the actual thresholds for changed (46 days is now 1 month, not 2).
Add jscs task with options
Fix invalid octal number
Gruntfile.js now passes jscs
moment.js now passes jscs
All lang files pass jscs
All test files pass jscs
Merge pull request #1718 from ichernev/jscs-support

Jscs support

@changelog
@section misc
@description code style checking with jscs (jshint is only for bug detection)