* merged from rugby471: - documentation updates - i18n fixes * softwarestore/view/gbwidget.py: - add new Gtkbuilder widget base class * softwarestore/view/appview.py: - allow a empty AppView * softwarestore/view/installedpane.py: - composited widget that contains navigation, applist and search for the installed software * softwarestore/view/availablepane.py: - composited widget that contains navigation, applist and search for the available software * softwarestore/view/searchentry.py: - make the icon_theme optional * make the status bar display the current number of items displayed * center the status bar (LP: #424895) * make menuitems "Copy", "Copy Weblink", "Software Sources" work * updated po files from rosetta * make the default size bigger (LP: #425862) * merged the fixes from Murat Güneş (many thanks!) * when using the navigation bar to navigate back one (or more) elements, remove the elements from the navigation bar (LP: #425810) * do not show "Search in Category", "Search in all" buttons. Instead do the follwing: - If the user clicks on "Get Free Software" while doing a search in a sub-Category clear the search and go to the Category screen. - If the user does click on the same button while doing a search that originates from the Category screen do not clear the search and go back to the list of the search results (and not to the Category screen). The search must be cleared with the cleared via the search field in this case. (LP: #425809) * softwarestore/view/searchentry.py: - show/hide the clear item based on if there is text in it or not * help updates (thanks to Matthew Paul Thomas) * make the progress bar less cramped (LP: #426281) * make default icon size in category view 48px * merged lp:~mpt/software-store/css branch (many thanks)