Use new installer feature from packager.io

Postinstall for openproject is now in its own addon at https://github.com/pkgr/addon-openproject.
Add addon-legacy-installer
allow flash messages to be permanent
when a query cannot be loaded, let angular display an error message
add 'show' action to QueryPolicy
return a 404 when accessing a not-viewable query via the experimental API
renaming queries renames it's menu item
simplify index action on exp.api work_packages_controller
Show unsupported browser notice for Firefox 10-30

We only support Firefox >= 31 (latest ESR) now. As we previously
supported older Firefox versions, especially 24, we show an
unsupported browser notice for them now.
add experimental-api query permission specs
add specs for QueryPolicy:show
no need to check for performed? in exp.api wp-controller
Allow to set link bg and font color
Allow to set font color for filtered entries
Rename CSS class for selected queries
Merge pull request #2033 from opf/fix/query_menu_item_renaming
Fix tests depending on CSS class 'first'
Move 'click' event to list entry element
fix query_loading spec
Merge pull request #2039 from opf/fix/mark_firefox_older_than_31_as_unsupported

Show unsupported browser notice for Firefox 10-30