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
simplification of lb.js implementation
Fixing Belarusian language
Fixing code style errors
Fix local to utc/zone switching with keepLocalTime option
Merge pull request #1738 from ichernev/bugfix-zone2

Fix local to utc/zone switching with keepLocalTime option
Merge pull request #1708 from ptbrowne/perf-makeDateFromInput

perf(makeDateFromInput): no need to match regex if input is a Date
Merge pull request #1720 from tentwentyfour/develop

simplification of lb.js implementation
Improve comments in a few tests
Remove padding newlines in the begining of functions
Merge pull request #1755 from ichernev/fix-jscs

Remove padding newlines in the begining of functions
Change duration.toIsoString to duration.toISOString. Closes #1752
Fixing Belarusian language
Fixing code style errors
deprecate pre-2.0 add/subtract
Fixed tests according to changes in #1642, see @icambron's last comment
Fixing merge conflicts
Convert double quotes to single quotes in moment.js
Simplify readme

 * Move the changelog to its own file
 * Make badges look like moment-timezone