See ChangeLog for fixes and additions

2001/11/15 Version 1.5: for "group", changed
           "NUMBER", "FRACTION", "PERCENT" to
           "#", "/", "%", respectively and
           allow variables to follow, after
           starting and direction specification,
           if any, and don't count observation if
           any of those variables has a nonfinite
           value.
2001/10/15 Version 1.4: minimum and maximum points of
           histograms can now be specified.
2001/09/22 Version 1.3: incorporated weighted
           percentiles into function "pctile"; renamed
           functions "probn" and "npoint" to "probz" and
           "zpoint", respectively.
2001/09/15 Renamed functions "invprobchisq", "invprobf",
           "invprobn", and "invprobt" to "chisqpoint",
           "fpoint", "npoint", and "tpoint", resp.
2001/09/14 In version 1.2, the capabilites and syntax
           of functions "plotlinreg" and "plotlogreg"
           have been modified to allow processing of
           datasets that are partitioned.
