Use 12-hour clock for :en-US and :en-CA

Fixes #335

In addition for time:formats:defaults the time zone as been modified from 'time zone as hour and minute offset from UTC' to 'time zone abbreviation name' to match common US usage as used for example by the US Naval Observatory (http://tycho.usno.navy.mil/timer.html) and the New York Times.
Merge pull request #368 from digitalfrost/patch-335

Use 12-hour clock for :en-US and :en-CA
Fixed date.formats.default in en-US locale
Merge pull request #369 from manzhikov/master

Fixed date.formats.default in en-US locale
more idiomatic zh-hk expressions
Merge pull request #370 from heartsentwined/idiomatic-zh-hk

more idiomatic zh-hk expressions
add missing translations
mark zh-hk as complete
Add zh-HK to the list of complete locales
Fix translations for less_than_x_{minutes,seconds} (ja)

Issue #374
Update ru.yml
Merge pull request #375 from mafiose/patch-1

Update ru.yml
Making Hungarian datetime.distance_in_words translations much nicer with proper endings
Merge pull request #376 from vadviktor/master

Making Hungarian datetime.distance_in_words nicer
Update the currency unit for pl.yml
Update the currency unit for fr-CH.yml
Merge pull request #379 from kainage/master

Added 2 currency units for pl and fr-CH
Bump rspec-rails to 2.14.0
Release the version 4.0.0 [skip-ci]
fix typos