fix criteria for document categories in sidebar

• document categories check for custom list elements need to exclude externally managed documents like query itself
• show name including hint that category is externally managed
fix criteria for document categories in sidebar

• document categories check for custom list elements need to exclude externally managed documents like query itself
• show name including hint that category is externally managed
fix whitespace and tabs
fix join type for externally managed categories

• requires inner join to exclude externally managed documents
replaced template chooser select by button menu

• dashboard_control.possibleTemplates returns now html with button and menu elements
• added test css and image for dashboard template icon graphics
• implemented experimental js code in dashboard_admin.js, which doesn't work
merge forgotten master changes
Merge branch 'dashboard_template_chooser' of github.com:/rapila/cms-base into dashboard_template_chooser