Adapt SDL ports to API changes

Fixes #90.

run/numptyphysics.run

@@ -10,7 +10,7 @@ set app_config {
 		<config> <default-policy writeable="yes" root="/"/> </config>
 	</start>
 
-	<start name="numptyphysics" priority="-2">
+	<start name="numptyphysics" priority="-2" caps="200">
 		<resource name="RAM" quantum="64M"/>
 		<config>
 			<libc stdout="/dev/log" stderr="/dev/log" >
@@ -29,7 +29,6 @@ set boot_modules {
 	freetype.lib.so
 	jpeg.lib.so
 	libc.lib.so
-	posix.lib.so
 	libm.lib.so
 	libpng.lib.so
 	pthread.lib.so