Update to v0.4.0

Change: Only network downloads are now shown on the downloads tab
Change: Clicking on a sub-tab (Filter, Sort, Display) in the local or
find content tabs toggles the visibility of the options
Change: Removed Popular sub-tab from Spotlight tab.
Change: Content you have installed appears greyed out in the Find
Content list.
Change: Removed Show/Hide Options button
Change: Removed debug setting controls
Change: Removed download section label
Change: Removed Upload tab for now
Change: Added Select All, Select None to the Local and Find Content tabs
Change: Removed some logging.
Bugfix: When scanning for local files, content stores now correctly only
return a list of new/updated content (if using the in-built method).
Bugfix: Reinstalling or updating a plugin now unloads and re-loads it
API: Added pahub.api.content.selectAll
API: Added pahub.api.content.selectNone