Add sidebar

[giplt]

Adding a side bar to hypha helps to split content (stays in menu) and other functionality on a website: search, content driven read more suggestions, log report et cetera. To be implemented in the vein of a taskbar panel

• [ ] sidebar generator
• [ ] implement widget definition: html + macro’s
• [ ] sidebar admin editor, pick from widget collection: search, read more, wym, log, ...