Handle textInput events in EditorComponent instead of on InputComponent

This commit also changes input handling to be more like it was in the
previous editor. We're using textInput rather than input events because
they are emitted *before* characters are inserted, enabling much simpler
detection of characters inserted via the accented-character menu on
OS X.

Previously I avoided this because something about it was causing reflows
in the old editor, but in this editor that doesn't seem to be a problem,
and it's actually faster.
Don't call preventDefault for spaces to prevent browser scrolling
Upgrade to markdown-preview@0.77
Don't assign scrollLeft on model on 'scroll-left-changed' events

Fixes #2513

I'm not entirely sure why, but for some reason we're getting into an
feedback cycle when the scrollLeft position changes in certain cases. In
theory, this shouldn't happen because reassigning the same value
shouldn't emit a change event. But since we're about to end-of-life the
jQuery editor, I'd like to try fixing it this way for now.
Upgrade to markdown-preview@0.78
Log message for all commands

The first time you bootstrap, all the build modules and apm are
installed. Previously this was showing no output so it was unclear
whether things are hung or now.

This will also help easily identify which stage of the build
npm and node-gyp errors are occurring.
:memo: Add git req to linux build instructions

Pretty simple, but doesn't come on a clean install.
Merge pull request #2602 from joliv/patch-1

Add git req to linux build instructions
Always pass windows build until flaky specs pass
Remove unused variable
Zip built app on Windows
Try 7za
Speed up built temporarily by not running specs
Use full path
Log directory
Add a command
Renable asset uploading
:memo: Document invalid .vcxproj file error

Refs #2430
Load atomcredentials on Windows
Add missing path segment