Revert "simplifying diff. Fixes #1227"

This reverts commit f4376a3e646802be099d90cd2aa20fd2123a6fc9.
Fix calendar bug related to DST and zones

We need the start of today, in either local time or utc (zone) time. We can not
assume that local time is the same as utc (current zone), because that changes
with DST.
Parse for tz from the right in zone(), fixes #1336
Make parseZone() use the format-specified timezone if available
Add test for parseZone TZ inference case
Support 2-digit HH timezones as valid ISO 8601 (fixes #1357)
Merge pull request #1347 from pimterry/fixZoneParsing

Fix zone parsing in potentially ambiguous cases (fixes #1336)
Make colon in ISO timezone format acceptable only when minutes are specified (+01:00 good, +01: bad)
Merge pull request #1358 from pimterry/supportIsoMMTimezones

Support 2-digit HH timezones as valid ISO 8601 (fixes #1357)
Add Merdiem Parse support for Korean Languages.
Test case was added for Korean Meridiem Parser support.
A space is added to test code.
Apply coding convention
Applied failed test result
Fix issue link in readme
Merge pull request #1364 from mc10/patch-1

Fix issue link in readme
Removed unecessary 'i' flag.

There is no capped letter in Korean.
Merge pull request #1362 from jeeeyul/develop

Meridiem Parser support for Korean
Merge pull request #1370 from ichernev/bugfix/proper-diff-timezone-correction

Bugfix/proper diff timezone correction
Fix isSame for differently zoned moments

isSame uses startOf and then compares milliseconds, but this misses the case of
different zones across the moments. startOf('day') in one timezone is different
than the other, so it was never successful.