added before/after date field to the download page.  Also re-compiled the recurse program which was written in C.  Apparently upgrading the linux version caused this program to fail.
added before/after date field to the download page.  Also re-compiled the recurse program which was written in C.  Apparently upgrading the linux version caused this program to fail.


paleobiodb/pbdb-new,paleobiodb/pbdb-new,paleobiodb/pbdb-new,paleobiodb/pbdb-new,paleobiodb/pbdb-new