Feature/custom i rt

A new pull request based on #2 . I worked on the code a little bit

- general code cleanup, moved some helper functions to OpenSwathHelper (that was on my table)
- renamed functions according to the OpenMS coding conventions
- adopted the CLI now using `-outlierDetection:outlierMethodIterative` which is either "jackknife" or "largest_residual" 
- added TOPP tests for `-estimateBestPeptides` and `-outlierDetection:outlierMethodIterative largest_residual` parameter
- adopted the Python bindings (not tested!)

Remaining TODOs: 
- see https://github.com/hroest/OpenMS/commit/6493912c178ba572f3d5eb9064497f3f6df9be6d
- still unresolved: `double max_rt_threshold = (RTRange.second - RTRange.first) / 30;` which will probably only work for iRT space and not any other RT space

what do you think?