…ing emojis

Adds new emojis based on the finalized [Emoji 5.0
spec](http://unicode.org/reports/tr51/index.html). Modifications to
some existing emojis included as well, see change list below for
specifics.

This change also moves the Twemoji version number to 2.3.

### New

* Star-Struck
* Face With Raised Eyebrow
* Exploding Head
* Crazy Face
* Face With Symbols Over Mouth
* Face Vomiting
* Shushing Face
* Face With Hand Over Mouth
* Face With Monocle
* Child
* Adult
* Older Adult
* Woman With Headscarf
* Bearded Person
* Breast-Feeding
* Mage
* Woman Mage
* Man Mage
* Fairy
* Woman Fairy
* Man Fairy
* Vampire
* Woman Vampire
* Man Vampire
* Merperson
* Mermaid
* Merman
* Elf
* Woman Elf
* Man Elf
* Genie
* Woman Genie
* Man Genie
* Zombie
* Woman Zombie
* Man Zombie
* Person in Steamy Room
* Woman in Steamy Room
* Man in Steamy Room
* Person Climbing
* Woman Climbing
* Man Climbing
* Person in Lotus Position
* Woman in Lotus Position
* Man in Lotus Position
* Love-You Gesture
* Palms Up Together
* Brain
* Orange Heart
* Scarf
* Gloves
* Coat
* Socks
* Billed Cap
* Zebra
* Giraffe
* Hedgehog
* Sauropod
* T-Rex
* Cricket
* Coconut
* Broccoli
* Pretzel
* Cut of Meat
* Sandwich
* Bowl With Spoon
* Canned Food
* Dumpling
* Fortune Cookie
* Takeout Box
* Pie
* Cup With Straw
* Chopsticks
* Flying Saucer
* Sled
* Curling Stone
* Flag for England
* Flag for Scotland
* Flag for Wales

### Modified

* Index Pointing Up
* Person Facepalming
* Man in Business Suit Levitating
* Person Getting Massage
* Hamburger
* Ogre
* Full Moon With Face
* New Moon Face
* First Quarter Moon With Face
* Last Quarter Moon With Face
* Japanese "vacancy" button