newline handling

In light of the recent 'bad options' feedback issue where \r messed
up message display, try to to make newline handling be more consistent.
I'm sure there are lots of places that still handle \n manually, but
it's a start.

src/files.c

@@ -2563,7 +2563,7 @@ read_config_file(filename, src)
 const char *filename;
 int src;
 {
-    char buf[4 * BUFSZ], *p;
+    char buf[4 * BUFSZ];
     FILE *fp;
     boolean rv = TRUE; /* assume successful parse */
 
@@ -2581,13 +2581,7 @@ line at this level.
 OR: Forbid multiline stuff for alternate config sources.
 */
 #endif
-        if ((p = index(buf, '\n')) != 0) {
-            /* in case file has CR+LF format on non-CR+LF platform */
-            if (p > buf && *(p - 1) == '\r')
-                --p;
-            *p = '\0'; /* strip newline */
-        }
-        if (!parse_config_line(fp, buf, src)) {
+        if (!parse_config_line(fp, strip_newline(buf), src)) {
             static const char badoptionline[] = "Bad option line: \"%s\"";
 
             /* truncate buffer if it's long; this is actually conservative */
@@ -3505,7 +3499,6 @@ char *nowin_buf;
 unsigned oid; /* book identifier */
 {
     dlb *fp;
-    char *endp;
     char line[BUFSZ], lastline[BUFSZ];
 
     int scope = 0;
@@ -3556,18 +3549,14 @@ unsigned oid; /* book identifier */
     *line = *lastline = '\0';
     while (dlb_fgets(line, sizeof line, fp) != 0) {
         linect++;
-        if ((endp = index(line, '\n')) != 0)
-            *endp = 0;
+        (void) strip_newline(line);
         switch (line[0]) {
         case '%':
             if (!strncmpi(&line[1], "section ", sizeof("section ") - 1)) {
                 char *st = &line[9]; /* 9 from "%section " */
 
                 scope = SECTIONSCOPE;
-                if (!strcmpi(st, tribsection))
-                    matchedsection = TRUE;
-                else
-                    matchedsection = FALSE;
+                matchedsection = !strcmpi(st, tribsection) ? TRUE : FALSE;
             } else if (!strncmpi(&line[1], "title ", sizeof("title ") - 1)) {
                 char *st = &line[7]; /* 7 from "%title " */
                 char *p1, *p2;