:lipstick: Deprecate backspaceToBeginningOf{Word,Line}

Rename functions `backspaceToBeginningOfWord` to `deleteToBeginningOfWord` and
`backspaceToBeginningOfLine to `deleteToBeginningOfLine`.
Rename commands `editor:backspace-to-beginning-of-word` to
`delete-to-beginning-of-word` and `editor:backspace-to-beginning-of-line` to
`editor:delete-to-beginning-of-line`.

Fix #1791
:memo: Add more Emoji to the contributing guide

Suggest Emoji for:
 - Fixing something on Mac OS
 - Fixing a bug
 - Burning whitespace
 - Fixing the CI build
 - Adding tests
 - Refactoring
 - Security
Include Terms of Use in the help menu
:memo: Clean up Config::observe
Check for e.ctrlKey instead of e.metaKey if not on Mac.
Upgrade to autoflow@0.17.0
Upgrade to language-gfm@0.36.0
Upgrade to language-ruby@0.24.0
Upgrade to language-gfm@0.37.0
Upgrade to archive-view@0.31.0
Upgrade to language-javascript@0.26.0
Use :apple: for Mac OS specific bugs
Merge pull request #2232 from atom/TOS-help

Include Terms of Use in the help menu
Merge pull request #2243 from lee-dohm/doc-fix

:memo: Clean up Config::observe
:memo: Mention previous value is in second argument object
Merge pull request #2246 from Flannelhead/master

Make ctrl+click add a new cursor in Linux and Windows, fixes #2105
:lipstick: Use trailing if
Use :fire: emoji for general deleting of code
Remove :recycle: from the emoji in CONTRIBUTING.md
Upgrade to fs-plus 2.2.3