Issues with REST API page history

[senfmal]

see commit 77061d6 :
error handling added as work-around when version history data is not
available for some reason

code comments (line 83-85, ConfLastUpdated.py):
fresh page without history
TODO: Creation date of the initial page needs to be used in such cases
TODO: Other scenario is a problem with the REST API history display, investigation needed

[senfmal]

Problem seems not to be fresh pages but the expand=version tag, instead of expand=history. next commit will fix this.

[senfmal]

It looks like sometimes expand=version needs to be used, and sometimes expand=history. release_v0.6 will fix this by checking if the last updated date is available in one or another.