Name: read_spartan

   Purpose: read / return spartan fits files

   Input Parameters: 
      NONE

   Output Paramters:
      info - structure containing image info (from FITs header)
      data - 2d or 3d spartan images

   Keyword Parameters:
      ss -  which files to read  (pointer, ex: ss=indgen(10) reads first 10
      nodata  - switch - if set, dont read data (just return info)
      catalog - switch, if set, image info from Catalog (not FITS)
      bfiles  - switch, if set, read B (brightness files)
      pbfiles - switch, if set, read PB (polarized brightness files
      roll_corrected - switch, if set read roll corrected (B and PB only)
      filenames - (output) - spartan FITS files online
      text - (output) - one line / image text summary

   Calling Examples:
      read_spartan,info,/raw            ; raw image info from CATALOG 
      read_spartan,info,,/raw,/fits     ; Same from FITS headers (slower)
      read_spartan,info,data,ss=ss      ; read selected RAW images (SS)
      read_spartan,info,data,/b,ss=ss   ; read B files (brightness)
      read_spartan,info,data,/pb,ss=ss  ; read PB files (Polarized brightness)
      read_spartan,info,data,/pb,/roll ss=ss  ; roll-corrected (B or PB)

      read_spartan,info,data, ss=ss     ; (default: roll correected PB)'
      read_spartan,(any call), text=text ; Text summary returned in TEXT

     Sample Calling Sequence - read first 20 roll-corrected PB and display 
        read_spartan,ii,data,/roll,/pb,ss=indgen(20),text=text	
        xstepper,data,text

   21-March-1996 (S.L.Freeland) Written
   27-March-1996 (S.L.Freeland) add catalog, keyword and function
    3-April-1996 (S.L.Freeland) add /B and /PB switches
    4-April-1996 (S.L.Freeland) add /roll keyword, documentation additions
    5-April-1996 (S.L.Freeland) add /OB, /RAW, and TEXT keywords

 CALLS: ***
	BREAK_FILE [1], BREAK_FILE [2], BREAK_FILE [3], CONCAT_DIR [1], CONCAT_DIR [2]
	CONCAT_DIR [3], FILE_EXIST [2], MORE [1], MORE [2], SPARTAN_STR, anytim2ints [1]
	anytim2ints [2], break_file [4], concat_dir [4], extract_fid, fid2ex [1]
	fid2ex [2], file_exist [1], file_exist [3], file_list [1], file_list [2]
	get_spartan_info [1], get_spartan_info [2], mreadfits, restgen [1], restgen [2]
	str_replace [1], str_replace [2]
 CALLED BY:
	spartan_pb2fits, spartan_roll2fits [1]
   Restrictions:
      Note - /OB implies /ROLL_CORRECTED (uncorrected OB avail via /RAW set)