v0.3.0

• Several library utilities added: plotting.gridspec_inches, adaptive_coarsegrain, singleton interpolation, and colormaps.

• New tools: cooltools sample for random downsampling, cooltools coverage for marginalization.

• compute-saddle now saves saddledata without transformation, and the scale argument (with options log or linear) now only determines how the saddle is plotted. Consequently, saddleplot function now expects untransformed saddledata, and plots it directly or with log-scaling of the colormap. (#105)