add project files to ignore list
add dependency to ChemoSpec for Dist function
rewrite to get rid of spurious check warnings
rewrote .simplex:
- got rid of old definition
- added assertion for corresponding size of data and indices
- simplify working code
  column selection can be due to assertion
- added test
work on spectralDist:

- add dependency to amap::Dist
- push cos.dist into own function
- clean up spectralDist
- add documentation

M should not be centered! Centering changes e.g. the angle between the rows, i.e. the cosine distance.
bugfix: unit test