[API,INTERNAL] peak boundary structures added, Eigen splines replaced by CubicSplines2d
[TEST] class tests fixed
[TEST] TOPP tests fixed
[TEST] test for peak boundaries added
Merge remote-tracking branch 'upstream/develop' into feature/PeakPickerHiRes_boundaries
Merge pull request #847 from lars20070/feature/PeakPickerHiRes_boundaries

peak boundaries and new cubic splines for PeakPickerHiRes
[FIX] fix windows compile error

- windows complains about "redefinition; different linkage" which should
  be fixed if declaration and definition match.
Merge pull request #852 from hroest/fix/WindowsFix

[FIX] fix windows compile error (redefinition; different linkage)