Add a FORTRAN binary I/O callback

src/sphere/file_io.f

+      SUBROUTINE OPEN_FILE(UID,NAME,STA,MODE)
+      INTEGER, INTENT(IN):: UID
+      CHARACTER*64, INTENT(IN):: NAME
+      CHARACTER*8, INTENT(IN):: STA
+      CHARACTER*12, INTENT(IN):: MODE
+      OPEN(UNIT=UID, FILE=NAME, STATUS=STA(1:7), FORM=MODE(1:11))
+      END
+      SUBROUTINE CLOSE_FILE(UID)
+      INTEGER, INTENT(IN):: UID
+      CLOSE(UID)
+      END
+      SUBROUTINE READ_INT(UID, VALUE)
+      INTEGER, INTENT(IN):: UID
+      INTEGER, INTENT(OUT):: VALUE
+      READ(UID)VALUE
+      END
+      SUBROUTINE WRITE_COMPLEX(UID, RVAL, IVAL)
+      INTEGER, INTENT(IN):: UID
+      REAL*8, INTENT(IN):: RVAL, IVAL
+      COMPLEX*16:: VALUE
+      VALUE=COMPLEX(RVAL,IVAL)
+      WRITE(UID)VALUE
+      END
+      SUBROUTINE WRITE_DOUBLE(UID, VALUE)
+      INTEGER, INTENT(IN):: UID
+      REAL*8, INTENT(IN):: VALUE
+      WRITE(UID)VALUE
+      END
+      SUBROUTINE WRITE_INT(UID,VALUE)
+      INTEGER, INTENT(IN):: UID
+      INTEGER, INTENT(IN):: VALUE
+      WRITE(UID)VALUE
+      END