Fix configure script to prevent -Wimplicit-int errors

This replaces
	main(){return(0);}
with the proper form of
	int main(void){return(0);}

OK tb@

devel/cgdb/patches/patch-config_readline_check_version_m4

@@ -10,3 +10,12 @@ Index: config/readline_check_version.m4
  CFLAGS="$CFLAGS -I${ac_cv_rl_includedir}"
  LDFLAGS="$LDFLAGS -L${ac_cv_rl_libdir}"
  
+@@ -86,7 +86,7 @@ AC_CACHE_VAL(ac_cv_rl_version,
+ #include <stdlib.h>
+ #include <readline/readline.h>
+ 
+-main()
++int main(void)
+ {
+ 	FILE *fp;
+ 	fp = fopen("conftest.rlv", "w");

devel/sdlmm/patches/patch-configure

@@ -1,5 +1,15 @@
---- configure.orig	Mon Aug 13 21:39:00 2001
-+++ configure	Sun Feb  5 11:36:41 2006
+Index: configure
+--- configure.orig
++++ configure
+@@ -1178,7 +1178,7 @@ cat > conftest.$ac_ext << EOF
+ #line 1179 "configure"
+ #include "confdefs.h"
+ 
+-main(){return(0);}
++int main(void){return(0);}
+ EOF
+ if { (eval echo configure:1184: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
+   ac_cv_prog_cc_works=yes
 @@ -5876,7 +5876,6 @@ fi
      echo "$ac_t""no" 1>&6
    fi

devel/smpeg/patches/patch-configure

@@ -1,5 +1,15 @@
---- configure.orig	Sat Jan  7 17:32:32 2012
-+++ configure	Sat Jan  7 17:33:52 2012
+Index: configure
+--- configure.orig
++++ configure
+@@ -1055,7 +1055,7 @@ cat > conftest.$ac_ext << EOF
+ #line 1056 "configure"
+ #include "confdefs.h"
+ 
+-main(){return(0);}
++int main(void){return(0);}
+ EOF
+ if { (eval echo configure:1061: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
+   ac_cv_prog_cc_works=yes
 @@ -2001,9 +2001,10 @@ else
    cat > conftest.$ac_ext <<EOF
  #line 2003 "configure"

textproc/clo++/patches/patch-configure

@@ -1,6 +1,15 @@
 Index: configure
 --- configure.orig
 +++ configure
+@@ -906,7 +906,7 @@ cat > conftest.$ac_ext << EOF
+ #line 907 "configure"
+ #include "confdefs.h"
+ 
+-main(){return(0);}
++int main(void){return(0);}
+ EOF
+ if { (eval echo configure:912: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
+   ac_cv_prog_cc_works=yes
 @@ -1234,11 +1234,11 @@ fi
  XML_CONFIG_ERROR="
  *** You need to have libxml2 installed to use clo++