Updated SDL2 to use dlopen instead of load_add_on, as discussed on haikuports ML (#841)

* FIXED SDL2 2.0.4 patchset. SDL2 was no longer handling any events.

* Added recipe for SDL2 2.0.5

* Updated SDL to use dlopen instead of load_add_on for loading dynamic
libraries
This resolves issues with SDL2_mixer not finding required 3rd party
libs, such as libvorso.3

* Removed trailing whitespace

media-libs/libsdl2/libsdl2-2.0.5.recipe

@@ -6,7 +6,7 @@ software, emulators, and popular games."
 HOMEPAGE="http://www.libsdl.org/"
 COPYRIGHT="1997-2016 Sam Lantinga"
 LICENSE="Zlib"
-REVISION="1"
+REVISION="2"
 SOURCE_URI="http://www.libsdl.org/release/SDL2-$portVersion.tar.gz"
 CHECKSUM_SHA256="442038cf55965969f2ff06d976031813de643af9c9edc9e331bd761c242e8785"
 SOURCE_DIR="SDL2-$portVersion"
@@ -24,6 +24,7 @@ REQUIRES="
 	haiku$secondaryArchSuffix
 	lib:libGL$secondaryArchSuffix
 	lib:libglu$secondaryArchSuffix
+	lib:libltdl$secondaryArchSuffix
 	"
 
 PROVIDES_devel="
@@ -42,6 +43,7 @@ BUILD_REQUIRES="
 	haiku${secondaryArchSuffix}_devel
 	devel:libgl$secondaryArchSuffix
 	devel:libglu$secondaryArchSuffix
+	devel:libltdl$secondaryArchSuffix
 	"
 BUILD_PREREQUIRES="
 	cmd:autoconf

media-libs/libsdl2/patches/libsdl2-2.0.5.patchset

@@ -241,3 +241,79 @@ index 36c2a1a..4676c58 100644
 -- 
 2.8.0
 
+diff -r fbf9b0e3589a configure
+--- a/configure	Sat Oct 22 17:53:03 2016 -0700
++++ b/configure	Wed Oct 26 20:14:55 2016 +0200
+@@ -23490,6 +23490,7 @@
+         CheckDummyVideo
+         CheckDiskAudio
+         CheckDummyAudio
++        CheckDLOPEN        
+         CheckHaikuVideo
+         CheckHaikuGL
+         CheckPTHREAD
+@@ -23518,14 +23519,6 @@
+             SOURCES="$SOURCES $srcdir/src/timer/haiku/*.c"
+             have_timers=yes
+         fi
+-        # Set up files for the shared object loading library
+-        if test x$enable_loadso = xyes; then
+-
+-$as_echo "#define SDL_LOADSO_HAIKU 1" >>confdefs.h
+-
+-            SOURCES="$SOURCES $srcdir/src/loadso/haiku/*.c"
+-            have_loadso=yes
+-        fi
+         # Set up files for the system power library
+         if test x$enable_power = xyes; then
+ 
+diff -r fbf9b0e3589a configure.in
+--- a/configure.in	Sat Oct 22 17:53:03 2016 -0700
++++ b/configure.in	Wed Oct 26 20:14:55 2016 +0200
+@@ -3229,6 +3229,7 @@
+         CheckDummyVideo
+         CheckDiskAudio
+         CheckDummyAudio
++        CheckDLOPEN
+         CheckHaikuVideo
+         CheckHaikuGL
+         CheckPTHREAD
+@@ -3251,12 +3252,6 @@
+             SOURCES="$SOURCES $srcdir/src/timer/haiku/*.c"
+             have_timers=yes
+         fi
+-        # Set up files for the shared object loading library
+-        if test x$enable_loadso = xyes; then
+-            AC_DEFINE(SDL_LOADSO_HAIKU, 1, [ ])
+-            SOURCES="$SOURCES $srcdir/src/loadso/haiku/*.c"
+-            have_loadso=yes
+-        fi
+         # Set up files for the system power library
+         if test x$enable_power = xyes; then
+             AC_DEFINE(SDL_POWER_HAIKU, 1, [ ])
+diff -r fbf9b0e3589a src/dynapi/SDL_dynapi.c
+--- a/src/dynapi/SDL_dynapi.c	Sat Oct 22 17:53:03 2016 -0700
++++ b/src/dynapi/SDL_dynapi.c	Wed Oct 26 20:14:55 2016 +0200
+@@ -216,21 +216,7 @@
+     return retval;
+ }
+ 
+-#elif defined(__HAIKU__)
+-#include <os/kernel/image.h>
+-static SDL_INLINE void *get_sdlapi_entry(const char *fname, const char *sym)
+-{
+-    image_id lib = load_add_on(fname);
+-    void *retval = NULL;
+-    if (lib >= 0) {
+-        if (get_image_symbol(lib, sym, B_SYMBOL_TYPE_TEXT, &retval) != B_NO_ERROR) {
+-            unload_add_on(lib);
+-            retval = NULL;
+-        }
+-    }
+-    return retval;
+-}
+-#elif defined(unix) || defined(__unix__) || defined(__APPLE__)
++#elif defined(unix) || defined(__unix__) || defined(__APPLE__) || defined(__HAIKU__)
+ #include <dlfcn.h>
+ static SDL_INLINE void *get_sdlapi_entry(const char *fname, const char *sym)
+ {