added file to cluster.split output. added warning to lefse code. fixed outputdir bug in make.group command.  added taxon table to biom format in make.shared command. added pdiffs to reverse primers
added pdiffs to reverse primers.
ignoring xcuserdata
ignoring project.xcworkspace
fixed issue with sffinfo and parse.fastq groups parse. added project.xcworkspace to .gitignore.
Merge remote-tracking branch 'origin/master'