introduction of ContentBaseView

preparation for generic button-handling - this commit may be buggy!
server response can (also) define target

target can given via action AND also be set in the  json returned by server via "page.target". the later overwrites the first
introduction of ContentBaseView

preparation for generic button-handling - this commit may be buggy!
reconstitution of some lost changes
buttons for all page-types

closed issue #1
code cleanup
mock.cgi: example for simple text-view
modal view (begin...)
Render page in modal window

issue #13

modal windows can contain tabs
if a form is rendered in a modal, (or tab), it will stay in the modal (or tab) throughout the submit/action process
Merge remote-tracking branch 'dsiebeck/feature/webui' into feature/webui
hotfix - login error
Merge remote-tracking branch 'dsiebeck/feature/webui' into feature/webui