Merge pull request #2 from sneumann/april2013hackfest

Fixes if XCMS did not find any peaks
Updated citation
Reanalyzed peaks comment in record; overridable annotator
Merge remote-tracking branch 'origin/april2013hackfest' into april2013hackfest
fixed low vs high settings across board
updated vignette, builds in RStudio, error in R CMD check
finished updating settings and vignette, roxygenized changes
Merge branch 'april2013hackfest' of github.com:sneumann/RMassBank into april2013hackfest