neverball: Needs c99 and avoid vsnprintf(3) hacks

- On NetBSD (and probably other operating system) the build failed
  because due `extern int vsnprintf(char *, size_t, const char *, va_list);'
  and SSP use.  `-std=c99' is already passed to the compiler
  and vsnprintf(3) is part of C99 so avoid the `extern'.
- Add LICENSE

Bump PKGREVISION

Problem noticed and original patch by chardar with little adjustments
from me, thanks a lot!

Index: Makefile
===================================================================
RCS file: /cvsroot/pkgsrc/games/neverball/Makefile,v
retrieving revision 1.34
diff -u -p -r1.34 Makefile
--- Makefile	14 Jan 2018 17:34:00 -0000	1.34
+++ Makefile	6 Oct 2018 19:26:17 -0000
@@ -1,16 +1,19 @@
 # $NetBSD: Makefile,v 1.34 2018/01/14 17:34:00 rillig Exp $
 
 DISTNAME=	neverball-1.6.0
-PKGREVISION=	1
+PKGREVISION=	2
 CATEGORIES=	games
 MASTER_SITES=	http://neverball.org/
 
 MAINTAINER=	pkgsrc-users@NetBSD.org
 HOMEPAGE=	https://neverball.org/
 COMMENT=	Puzzle/action game similar to Super Monkey Ball
+LICENSE=	gnu-gpl-v2
 
 USE_TOOLS+=	gmake pax
 
+USE_LANGUAGES=	c99
+
 # Avoiding multiples patches...
 BUILDLINK_FNAME_TRANSFORM.SDL+=		-e "s|/SDL/|/|g"
 BUILDLINK_FNAME_TRANSFORM.SDL_ttf+=	-e "s|/SDL/|/|g"
Index: distinfo
===================================================================
RCS file: /cvsroot/pkgsrc/games/neverball/distinfo,v
retrieving revision 1.10
diff -u -p -r1.10 distinfo
--- distinfo	3 Nov 2015 20:57:00 -0000	1.10
+++ distinfo	6 Oct 2018 19:26:17 -0000
@@ -5,4 +5,5 @@ RMD160 (neverball-1.6.0.tar.gz) = 3489fc
 SHA512 (neverball-1.6.0.tar.gz) = 174d05308aee3a5e693782c54dd389439752b3597f28193771041d30f6c4236a5d055b2fcca9460b1005e9f000ddb3cbc01b86ea15c2abbf6e5a7996e836f787
 Size (neverball-1.6.0.tar.gz) = 37772911 bytes
 SHA1 (patch-ab) = 3cca20f42390d22c73c03171f725fe562f73cb0d
+SHA1 (patch-share_common.h) = f7f68029ab39d10dd025557c14f122b9980e437c
 SHA1 (patch-share_solid__draw.h) = 85b3271eb10056f19d79688fca305464063752ba
Index: patches/patch-share_common.h
===================================================================
RCS file: patches/patch-share_common.h
diff -N patches/patch-share_common.h
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ patches/patch-share_common.h	6 Oct 2018 19:26:17 -0000
@@ -0,0 +1,22 @@
+$NetBSD$
+
+C99 is already passed via CFLAGS and vsnprintf(3) is part of it.
+
+--- share/common.h.orig	2014-05-21 13:21:43.000000000 +0000
++++ share/common.h
+@@ -81,15 +81,6 @@ char *concat_string(const char *first, .
+ #define str_starts_with(s, h) (strncmp((s), (h), strlen(h)) == 0)
+ #define str_ends_with(s, t) ((strlen(s) >= strlen(t)) && strcmp((s) + strlen(s) - strlen(t), (t)) == 0)
+ 
+-/*
+- * Declaring vsnprintf with the C99 signature, even though we're
+- * claiming to be ANSI C. This is probably bad but is not known to not
+- * work.
+- */
+-#ifndef __APPLE__
+-extern int vsnprintf(char *, size_t, const char *, va_list);
+-#endif
+-
+ /* Time. */
+ 
+ time_t make_time_from_utc(struct tm *);