Fix some spaces around "<-"
Added a TODO file
Piping %>% some examples
Fix untangle tests: untangle_step_rotate_1side now outputs a dendlist, so we needed to extract the first element so to get the same results as before.
(also added piping)
Added match.arg for Bk_plot,  cor_cophenetic, entanglement, untangle_random_search, untangle_step_rotate_1side, and untangle_step_rotate_2side
Added entanglement.dendlist to the doc
Added cor_cophenetic.dendlist with tests and docs.

(also minor fix to the cor bakers gamma test)
update.dendrogram - first draft of the function (implements only "labels")
`labels_colors<-` now has a default behavior if value is missing.
color_branches - now has a default behavior if k is missing.

Also made some cleaning up for the color_branches code. As well as added a new alias.
plot.dendlist - a wrapper for tangelgram