[js utils] backport some generic code from comments cube
to handle inline ajax form as you get to add comment to entities.
Following stuff has been generalized and backported to ease such things:
* lazy_view_holder() method on EntityCtxComponent class, to build
place holder where the form will be inserted
* ajax_composite_form() function in cw.web.views.ajaxedit, to build
the form itself
* reload() and reloadCtxComponentsSection() javascript function in
cubicweb.ajax.js for the javascript processing side
# copyright %(year)s %(author)s, all rights reserved.
# contact %(author-web-site)s -- mailto:%(author-email)s
#
%(long-license)s
"""%(distname)s precreate script, executed at instance creation time or when
the cube is added to an existing instance, before the schema is serialized.
This is typically to create groups referenced by the cube'schema.
"""