add folder option to sidebar styling
remove whitespace
minimized folder keeps the gray color
make workspace sidebar use a singleton instead of inferring

EpubContainer for gh-book and WorkspaceRoot for atc
add code to hide Book Picker title
use with with opacity instead of specific colors

toc-color-light is still in use elsewhere, so leaving it in
Merge branch 'master' into atc-sidebar-folder-styling

Conflicts:
	styles/variables.less
if model does not have .findDescendantDFS then use the original model
for pointer events splice in the pointer model

this causes problems when filteredCollection tries to keep its
collection in sync
remove unused (and poorly defined) trigger

it should at the very least send @ as an argument
Merge branch 'master' into atc-root-singleton

Conflicts:
	scripts/gh-book/app.coffee
Merge branch 'master' into atc-root-singleton

Conflicts:
	scripts/gh-book/app.coffee
add explicit dependency for filtered-collection
Merge remote-tracking branch 'origin/master' into atc-root-singleton
Merge remote-tracking branch 'oerpub/atc-sidebar-folder-styling' into github

Conflicts:
	styles/workspace/sidebar.less
remove dangling merge conflict
Merge remote-tracking branch 'oerpub/dependency-for-filteredcollection' into github
Merge remote-tracking branch 'oerpub/atc-root-singleton' into github
add fix so new Modules are added properly to the Workspace
Merge branch 'github' into atc-update

Conflicts:
	scripts/gh-book/app.coffee
	scripts/gh-book/epub-container.coffee