Render timetables in templates

As discussed on the merge day, IE8 gives up when rendering a lot of timetables on one page. This PR moves table rendering to the page templates.

@href i assumed that there is always exactly one reservation per ``reservation-summary``, is this correct? If not this PR needs some work.

:exclamation: this PR is based on seantis/seantis.reservation#84 please merge that one first.