Closes #2753

Closes #2855

Closes #2874

Issue #2884

The artist who drew the new logo

Trying to call endOperation on a half-constructed editor will never end
well, and the resulting errors will mask the actual error that happened.

Issue #2870

Changed background selected color to #303030, previous #202020 value is too dark.
https://github.com/cristatus/brackets-darker/issues/12

To be more intelligent about what kind of lines to indent.

Closes #2866

- Using `@` as `this`
- `and=` and `&&=`
- `or=` and `||=`
- `?=`

Closes issue #2832