Fixes #2022, do not resume on Android when surfaceChanged

If the app is in landscape mode and the user presses the power button, a pause
is followed immediately by a surfaceChanged event because the lock screen
is shown in portrait mode. This triggers a "false" resume.
So, we just pause and resume following the onWindowFocusChanged events.

Also, wait for SDL_APP_WILLENTERBACKGROUND and SDL_APP_DIDENTERBACKGROUND before
blocking the event pump.

build-scripts/strip_fPIC.sh

@@ -0,0 +1,21 @@
+#!/bin/sh
+#
+# libtool assumes that the compiler can handle the -fPIC flag
+# This isn't always true (for example, nasm can't handle it)
+command=""
+while [ $# -gt 0 ]; do
+    case "$1" in
+        -?PIC)
+            # Ignore -fPIC and -DPIC options
+            ;;
+        -fno-common)
+            # Ignore -fPIC and -DPIC options
+            ;;
+        *)
+            command="$command $1"
+            ;;
+    esac
+    shift
+done
+echo $command
+exec $command