Added phasing tutorial for PHYLUCE

iupac consensus script

shuffle snps script

add filter to only extract phylogenetically informative sites (at least 2 occurrences of new variant)

added script to format snp nexus for BEAST

added function to exclude taxa from tree (root_trees.r)

added r-script to root trees

small cleanup

bugfix

small fix

added credits

added script to reduce the size of log-files

added options to choose if only one or all snps per locus shall be extracted

added function to output all variable sites as sequence

Update README.md