Create a global option to follow symlinks in project-wide search

Fixes https://github.com/atom/find-and-replace/issues/271
:arrow_up: underscore-plus@1.6.6
:arrow_up: release-notes@0.40
Paste selection clipboard after finalizing selections
Track middle button mouse down events on Linux
Write to selection clipboard from setTimeout

This is so that in progress transactions aren't written to the
selection clipboard.
Use skinny arrow
Update spec for new middle mouse paste behavior
Merge pull request #4691 from atom/ks-improve-middle-mouse-paste

Improve middle mouse paste on Linux
:arrow_up: tree-view@0.139.0

For bug fixes
Prepare 0.163
:arrow_up: scoped-property-store@0.15.4

For performance improvements
Add explorer check using SystemRoot path

Closes #4551
Fall back to system root for cmd.exe path
:arrow_up: language-sass@0.29
:arrow_up: release-notes@0.41
:arrow_up: language-html@0.27.0

For handlebars template scope fix
Add `atom.inSafeMode()`
Pass the load settings through so all windows share devMode and safeMode
Default devMode and safeMode to false