+ o plot.phylo(direction = "l", x.lim = 30) failed to plot the branches
+ in the correct direction though the tip labels were displayed
+ correctly.
+
+
+OTHER CHANGES
+
+ o The c, cbind, and rbind methods for "DNAbin" objetcs now check that
+ the sequences are correctly stored (in a list for c, in a matrix
+ for the two other functions).
+