paralellized unifrac.weighted for windows. added get.metacommunity command. fixed...

paralellized unifrac.weighted for windows. added get.metacommunity command.  fixed bug in sequence class filterToPos that was effecting pcr.seqs trimming. {For forward primer trimming with aligned sequences and keepdots=t. If the character before the first primer base was a base and not a gap the base was not trimmed.} modified setFilePosFasta in mothurOut class to help with large files on 32bit machines.