Load the default themes in safe mode
Upgrade to atom-shell@0.15.4
Make menu bar auto-hide.
Fix indentation
Move coffeelint settings to external file

The motivation is for this is to allow `coffeelint` config to be shared by
`script/grunt coffeelint`, global `coffeelint` and inline linting via
`AtomLinter`.

Test Plan:

Made some deliberate lint errors then ran `script/grunt coffeelint` and
verified the output looked the same with and without this change.
Update linux.md

Clarify the build steps. The most important is that initialy "Create ..." and "Install ..." could be interpreted as "(User should) create/install ..." while it should mean "(To) create/install ... (do)".
Revert "Make menu bar auto-hide."

This reverts commit 64731bff468fbefa01583cece573ddd1f00656c0.
Upgrade to atom-shell@0.15.5
Merge pull request #3196 from atom/atom-shell-v0.15.4

Upgrade to atom-shell@0.15.4
Upgrade to base16-tomorrow-dark-theme
Merge pull request #3219 from wernight/patch-1

Update linux.md
Upgrade to bracket-matcher@0.52
Fixes unexecutable commands on win32 in BP

Signed-off-by: Luca Moser <moser.luca@gmail.com>
Merge pull request #3208 from XemsDoom/fix-win32-buffprocess

Fixes additional quotes on win32 in BufferedProcess
Merge pull request #3186 from maschs/ms-safeModeThemes

Load the default themes in safe mode
Allow any bundled theme when in safe mode

Check enabled names against the bundled names and ensure
one bundled UI and one bundled syntax theme are enabled,
defaulting to the dark themes when necessary.
Upgrade to language-sass@0.15
ignore no_unnecessary_fat_arrows too
Use grunt-coffeelint@0.0.13 instead of forked version

Test Plan:

```
$ ./script/grunt coffeelint
Running "coffeelint:src" (coffeelint) task
>> 80 files lint free.

Running "coffeelint:build" (coffeelint) task
>> 23 files lint free.

Running "coffeelint:test" (coffeelint) task
>> 40 files lint free.
Done, without errors.
```
Merge pull request #3218 from dmnd/coffeelint-config-file

Move coffeelint settings to external file