add URLs in comments for all libcurl function calls

docs/examples/adddocsref.pl

@@ -0,0 +1,35 @@
+#!/usr/bin/perl
+
+# pass files as argument(s)
+
+my $docroot="http://curl.haxx.se/libcurl/c";
+
+for $f (@ARGV) {
+    open(NEW, ">$f.new");
+    open(F, "<$f");
+    while(<F>) {
+        my $l = $_;
+        if($l =~ /\/* $docroot/) {
+            # just ignore preciously added refs
+        }
+        elsif($l =~ /^( *).*curl_easy_setopt\([^,]*, *([^ ,]*) *,/) {
+            my ($prefix, $anc) = ($1, $2);
+            $anc =~ s/_//g;
+            print NEW "$prefix/* $docroot/curl_easy_setopt.html#$anc */\n";
+            print NEW $l;
+        }
+        elsif($l =~ /^( *).*(curl_([^\(]*))\(/) {
+            my ($prefix, $func) = ($1, $2);
+            print NEW "$prefix/* $docroot/$func.html */\n";
+            print NEW $l;
+        }
+        else {
+            print NEW $l;
+        }
+    }
+    close(F);
+    close(NEW);
+
+    system("mv $f $f.org");
+    system("mv $f.new $f");
+}