Add stability message for Atom.io API

This indicates that the Atom.io API is not frozen - this is describing the state
of things, not announcing a new policy.
Upgrade to language-javascript@0.34
Render the line numbers after gutter mount

Fixes #2916
Install apm in 32-bit mode on Windows CI
Upgrade to apm@0.76
:memo: Doc --arch=ia32 flag
Merge pull request #2915 from atom/ks-32-bit-node-on-windows

Ship 32-bit node with apm on Windows
Move gutter member into a showLineNumbers observe block
Change shift-delete to trigger core:cut

Win32 and Linux keymaps
Merge pull request #2927 from batjko/master

Change shift-delete to trigger core:cut in Win32 and Linux
Check that args are present before mapping over

Closes #2925
Upgrade to language-javascript@0.35
Upgrade to metrics@v0.33.0
Upgrade to fuzzy-finder@0.57.0
Upgrade to apm@0.77
Prepare 0.115
Upgrade to tree-view@0.109.0
Merge pull request #2920 from atom/bo-gutter-toggle-api

Move gutter member into a showLineNumbers observe block
Merge pull request #2760 from atom/package-api-stability-notice

Add stability message for Atom.io API
Upgrade to markdown-preview@0.91