Please pull our changes

Most importantly, this makes the XCMS vignette compile and also works 
for https://github.com/sneumann/RMassBankDataIPBMM48 data. 

I would also opt to push this as 1.5.1 to BioC, so we have a few weeks 
to polish stuff, e.g. if we encounter build timeouts etc.

Yours,
Steffen