[FIX] as discussed in #822
[FIX] simplify code, as discussed in #822
[FIX] fix bug, as discussed in #822
[FIX] remove dead code, as discussed in #822
[FIX] sane input validation for CompressedInputSource
[FIX] remember whether RT was set or not
[FIX] at least initialized all members, in the proper order
[FIX] fix sorting for quantile computation
Merge pull request #846 from hroest/fix/fixesFrom822

Fix/fixes from822
Merge remote-tracking branch 'upstream/develop' into feature/PeakPickerHiRes_boundaries