DMRnet 0.4.0

• Variable selection algorithm var_sel added
• GLAMER implemented as a net version respective to its $\tau$ parameter (issue #57)
• Features package load message with citation info
• Fixing a problem with zero-length arrow in CV plots resulting from sd=0 (problem still remaining in issue #39 after the 0.3.2.9002 fix)
• Citation update
• Hierarchical clustering based on segmentation of 1D points with hclust1d package for PDMR and GLAMER