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.

autogen.sh

@@ -0,0 +1,19 @@
+#!/bin/sh
+#
+echo "Generating build information using autoconf"
+echo "This may take a while ..."
+
+# Regenerate configuration files
+cat acinclude/* >aclocal.m4
+found=false
+for autoconf in autoconf autoconf259 autoconf-2.59
+do if which $autoconf >/dev/null 2>&1; then $autoconf && found=true; break; fi
+done
+if test x$found = xfalse; then
+    echo "Couldn't find autoconf, aborting"
+    exit 1
+fi
+(cd test; sh autogen.sh)
+
+# Run configure for this platform
+echo "Now you are ready to run ./configure"