convert ASCII TABs to ASCII SPACEs

Converted all ASCII tabs to ASCII spaces using a 8 character
tab stop, for all files, except for all Makefiles (plus rpm.mk).
The `git diff -w` reports no changes.

help/credit

@@ -15,7 +15,7 @@ Credits
     hist.c which is used to do the command line editing.
 
     Thanks to Ernest W. Bowen for supplying many improvements in
-    accuracy and generality for some numeric functions.	 Much of
+    accuracy and generality for some numeric functions.  Much of
     this was in terms of actual code which I gratefully accepted.
     Ernest also supplied the original text for many of the help files.
 
@@ -26,17 +26,17 @@ Credits
 
     Most of this source and binary has one of the following copyrights:
 
-	Copyright (C) year  David I. Bell
-	Copyright (C) year  David I. Bell and Landon Curt Noll
-	Copyright (C) year  David I. Bell and Ernest Bowen
-	Copyright (C) year  David I. Bell, Landon Curt Noll and Ernest Bowen
-	Copyright (C) year  Landon Curt Noll
-	Copyright (C) year  Ernest Bowen and Landon Curt Noll
-	Copyright (C) year  Ernest Bowen
-	Copyright (C) year  Petteri Kettunen and Landon Curt Noll
-	Copyright (C) year  Christoph Zurnieden
-	Copyright (C) year  Landon Curt Noll and Thomas Jones-Low
-	Copyright (C) year  Klaus Alexander Seistrup and Landon Curt Noll
+        Copyright (C) year  David I. Bell
+        Copyright (C) year  David I. Bell and Landon Curt Noll
+        Copyright (C) year  David I. Bell and Ernest Bowen
+        Copyright (C) year  David I. Bell, Landon Curt Noll and Ernest Bowen
+        Copyright (C) year  Landon Curt Noll
+        Copyright (C) year  Ernest Bowen and Landon Curt Noll
+        Copyright (C) year  Ernest Bowen
+        Copyright (C) year  Petteri Kettunen and Landon Curt Noll
+        Copyright (C) year  Christoph Zurnieden
+        Copyright (C) year  Landon Curt Noll and Thomas Jones-Low
+        Copyright (C) year  Klaus Alexander Seistrup and Landon Curt Noll
 
     A few files in calc are covered under "The Unlicense".  For more
     information on this license, see:
@@ -50,8 +50,8 @@ Copying / Calc GNU Lesser General Public License
     Lesser General Public License.  You are welcome to change it and/or
     distribute copies of it under certain conditions.  The calc commands:
 
-	help copying
-	help copying-lgpl
+        help copying
+        help copying-lgpl
 
     should display the contents of the COPYING and COPYING-LGPL files.
     Those files contain information about the calc's GNU Lesser General
@@ -62,17 +62,17 @@ Copying / Calc GNU Lesser General Public License
     Lesser General Public License.  If you do not have these
     files, write to:
 
-	Free Software Foundation, Inc.
-	51 Franklin Street
-	Fifth Floor
-	Boston, MA  02110-1301
-	USA
+        Free Software Foundation, Inc.
+        51 Franklin Street
+        Fifth Floor
+        Boston, MA  02110-1301
+        USA
 
 See also:
 
-	help copyright
-	help copying
-	help copying-lgpl
+        help copyright
+        help copying
+        help copying-lgpl
 
 ## Copyright (C) 1999,2023  Landon Curt Noll
 ##
@@ -82,7 +82,7 @@ See also:
 ##
 ## Calc is distributed in the hope that it will be useful, but WITHOUT
 ## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
-## or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU Lesser General
+## or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General
 ## Public License for more details.
 ##
 ## A copy of version 2.1 of the GNU Lesser General Public License is
@@ -90,8 +90,8 @@ See also:
 ## received a copy with calc; if not, write to Free Software Foundation, Inc.
 ## 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 ##
-## Under source code control:	1991/07/23 05:47:24
-## File existed as early as:	1991
+## Under source code control:   1991/07/23 05:47:24
+## File existed as early as:    1991
 ##
-## chongo <was here> /\oo/\	http://www.isthe.com/chongo/
-## Share and enjoy!  :-)	http://www.isthe.com/chongo/tech/comp/calc/
+## chongo <was here> /\oo/\     http://www.isthe.com/chongo/
+## Share and enjoy!  :-)        http://www.isthe.com/chongo/tech/comp/calc/