Feature/bk tap tree

[ I thought I'd opened this this morning, but it seems I opened the pull request to the old repository on Nam's account]

I've added two new modules to rootana which save and load TAPs to a tree.
These should be seen as temporary kludges so we can do this without the event navigator.

The work is done by transferring the TAPs stored in gAnalysedPulseMap into a set of TClonesArrays. I'm not sure therefore how this will handle specialised TAPs therefore, but when the use case arises we can always tweak things.

@litchfld , I made some tweaks to the event navigator itself so I would like your blessing to merge this in first.  The changes were:
 - TGlobalData was being cleared directly in LoopSequence::Process and in `ClearGlobalData`.  I've taken it out ClearGlobalData now.  Im nervous this could cause new memory leaks, but I think in principle it's safe.
 - The Preprocess, Process and Postprocess methods only checked the return codes of the module's methods after passing over each module.  I've changed it so it checks it for each module, which I think is the more natural behaviour.

The branches made from SavePulses can be used interactively so we can do simple analysis with TTree::Draw from now on.  More complex stuff can then load the pulses back into the framework with the LoadPulses module.