Bootstrax updates and removing data from ebs

Created by: jorana

In this PR several bootstrax/bin changes are implemented mostly aimed at safely removing data from the eventbuilders.

Most importantly, I envisage a new script ajax for deleting old data from the eventbuilders. I think that as bootstrax is dynamically increasing quite some functionality is now aimed at removing data from the eventbuilders. By moving this functionality to a separate script bootstrax may become more clearly aimed at processing new data.

Furthermore there is a small change was made in the logic when to start up the old event builders (in case the new ones are swamped), we saw this recently if the buffers were full.

Please note that bootstrax is not using ajax at the moment (this is still a draft). I used it for cleaning stuff of the very old runs in the incorrect format we had when the buffers were filled up.

Additionally Darryl added several improvements as explained below.