93/02/01 - JR - vector.c
		added new option arrowhead_factor which allows user to
		specify factor by which to proportionately size the arrowhead;
		changed MAXNUMFILES and MAXLONLAT to smaller values for
		PC environment to fix stack overflow problem;
		changed arrow routine to draw circle instead of arrow
		also if velocities result in an arrowlength that is less
		than the arrowhead length (not only when velocity is 0).
93/02    - EF - vector.c
		added capability to create several plots with one control
		file by adding the "make_plot" and "add_plot" options
93/04/27 - JR - vecsub.c
		fixed bug in axis() and mapaxis() that used fabs instead of abs
		on nc parameter.  This caused the legend labeling (Velocity (cm/s))
		to disappear from the plots.  (I don't know how it used to work
		in the first place, unless the fabs() was less picky under old
		versions of the C compiler?)
94/05/20 - EF - vector.c
                Changed the way the longitude range is handled, so that negative
                longitudes are no longer automatically increased by 360.  Instead,
                longitudes exceeding the lon_range: minimum are increased and
                those exceeding the lon_range: max are decreased.  First, the
                input min and max are checked, and if the min exceeds the max
                (e.g. 170E to 170W, so min is 170, max is -170), then the max has
                360 added to it.

                Added two new options: first_subplot, last_subplot.  first_subplot
                before a make_plot or add_plot command turns off the "showpage"
                postscript command; last_subplot turns it back on.  Use first_subplot
                to start a series of subplots on a single page, last_subplot to
                end the series.  I have NOT done anything about the Postscript
                bounding box comments; these still pertain to the individual
                subplots, not to the whole page of subplots.

94/08/01 - JR - fixed bounding box calculations and page count
		to accommodate Eric's changes above

94/11/17 - SB - major revisions to add new features, including mercator projection,
		labels on plots, plot array, more user control on legend, etc.
		see codas3/vecplot/vector.doc for details
		control file options have been radically changed

94/11/25 - SB - added options for changing title font/size
95/04/18 - JR - fixed map drawing routines to work for any lon_range between
		-180 to 720 degrees; note: lon_range should cover no more than 360 degrees
95/05/16 - JR - extract:
                did some code reorganization made necessary because of the
                changes to drawmap.c routines--separated out some routines
                (connect, axis_crossed) to mapsub.c so extract can continue
                to use these;
              - vector:
                fixed problem in tick labelling due to roundoffs when
                step size is not integral; this required redefinition
                of the remainder function (frem) using long ints.

95/10/26 - EF - vector:
                fixed bug in bounding box lower left Y
                coordinate calculation
              - vecsub and vector:
                replaced "op_get_trans" with "op_get_param"
                plus additional steps to do the translation. 
                Translation in place simply is not possible
                with the option processing system as it is now
                designed, unfortunately.  Option processing
                requires functions that have as arguments a
                function pointer, an integer, and a character
                pointer.  To do a translation, one would need
                an additional pointer to the name list array;
                there is no way to get around this (short of
                using global variables), and one can't simply
                put a pointer in the place where the integer
                should be.