WIP anova
WIP t_contrast
DOC datasets
STY testnd:  move t-contrast to separate module
LOG permutation
OPT anova:  permute model instead of data
OPT opt:  remove perm argument
ENH ClusterDist:  store Eelbrain version
TEST perm:  anova, t_1samp
TEST testnd.anova reproducibility
STY _stats:  move stat functions from testnd -> stats
TEST stats
FIX stats.corr
ENH ClusterDist:  store init-time and host-name
ENH ClusterDist:  info-list
ENH colors:  colors for n-way designs
FIX combine:  combine dataset info
ENH MneExperiment:  drop unnecessary mne objects