Merge pull request #1238 from van51/feature/hashing

HashedDenseFeatures class
Fix issue #1239
object of type 'filter' has no len()
Fix issue #1240
change random seed to current time in 1/100s and change unit tests
removed warning
removed warning
compile with warnings as errors
removed warning
unit test for checking correct quantiles of std normal rnd
removed print output
Merge pull request #1241 from karlnapf/develop

some random fixes/changes/tests
remove sparse feature example since it were only tests
new unit tests for matrix
added test for equals
equals method and minor updates
dont allow transposed for subsetted features since it breaks tests
added a massive bunch of tests for subsets on sparse features
removed print
sped up test and reduce accuracy
Merge pull request #1244 from karlnapf/develop

Fix the failing sparse subset unit tests