Update code style

Limit source code to 80 chars, and declare functions return type and
modifiers on a separate line.

This allows to avoid very long lines, and all function names are
aligned.

(We do this on VLC, and I like it.)

app/src/sys/unix/net.c

@@ -2,15 +2,18 @@
 
 # include <unistd.h>
 
-SDL_bool net_init(void) {
+SDL_bool
+net_init(void) {
     // do nothing
     return SDL_TRUE;
 }
 
-void net_cleanup(void) {
+void
+net_cleanup(void) {
     // do nothing
 }
 
-SDL_bool net_close(socket_t socket) {
+SDL_bool
+net_close(socket_t socket) {
     return !close(socket);
 }