Load the default themes in safe mode
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)".
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
Upgrade to language-c@0.27
Add confirmation dialog to checkoutHead

There have been a few reports of files mysteriously going back to the
last version in the tree. My theory is that it is because of people
fat-fingering the Undo command because the default keyboard mapping is
too similar. This will at least prevent most accidental data loss.
Add config option for checkoutHead confirmation

Per the discussion with @kevinsawicki in #3168, I have added a config
option `editor.confirmCheckoutHead` that defaults to `true`. When the
`editor:checkout-head-revision` command is executed, a confirmation
dialog now shows that states which file is to be reverted and asks the
user to "Revert" or "Cancel". If the config option is set to `false`,
the old behavior, simply reverting without prompting, is used.

I also added tests to ensure that the confirmation dialog is displayed
or not in the right configurations.
Add a step to revert unsaved changes

I took the key part from PR #3183 and added it to the post-confirmation
flow.
Use beforeunload instead of unload

unload is asynchronous in Chrome 36 and so saving the state while
reloading may not happen before the state is read on the new render
process.
Only unload editor window when confirmed