timeline view minor enhancements
* support dates < 1900 by using logilab.common.date.ustrftime
* make the timeline a public member of the TimeLineWidget
* let buildWidget return the created widget, so that we can manipulate it later
Document: cubicweb-doc
Title: CubicWeb documentation
Author: Logilab
Abstract: Some base documentation for CubicWeb users and developpers
Section: Apps/Programming
Format: HTML
Index: /usr/share/doc/cubicweb-documentation/index.html
Files: /usr/share/doc/cubicweb-documentation/*.html