[TEST] add test for TraML file

- TraMLFile should be able to store a (valid) minimal example of a TraML
  file and read it again.
[API,INTERNAL] replace linear fit by B-spline in peak width estimation
[INTERNAL] B-spline wavelength adjusted
[FIX] ensure valid TraML file is written by not outputting a double equal to numeric limits
[FIX,PYOPENMS] add operators to TargetedExperiment
[FIX] add inequality operator
pxd files
[NOP] rearrange pychecker ignore
[TEST,PYOPENMS] add test
[API,INTERNAL] new implementation of PeakWidthEstimator
[FIX] improve set_peaks documentation

- write message what went wrong in assertion code
- fix typo
- reserve space for new data (for speed)
[API] removes PeakWidthEstimator_ from MultiplexClustering
[TEST] PeakWidthEstimator class test added
[API] free pointer in destructor
[API] virtual destructor used
[API] now passing const references
Merge pull request #1037 from hroest/fix/TraMLLoadStore

Fix/ TraML load/store
Merge pull request #1038 from hroest/feature/pyOpenMS_wraps

Feature/py open ms wraps
Merge pull request #1034 from hroest/fix/set_peaks

[FIX] improve set_peaks documentation
Merge pull request #1035 from lars20070/fix/FeatureFinderMultiplex

B-spline interpolation for peak width estimation in MultiplexClustering class