Install fixes, $prefix supported better, strip binaries and .so files

- Makefile fixes for installation, paths encoded wrong
- Strip binaries + .so files, support for $(CROSS) toolchain strip
- Default install is now to /sbin/finit and /usr/
- Use the 'plugindir' environemnt variable instead of 'PLUGIN_DIR'

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

finit.conf

@@ -0,0 +1,12 @@
+# Simple Debian finit.conf
+check /dev/vda1
+module evdev
+module loop
+module psmouse
+user admin
+host testbed
+network service networking start
+service /sbin/klogd -n -- Kernel logging server
+service /sbin/syslogd -n -- Syslog server
+service /usr/sbin/sshd -D -- OpenSSH server
+service /usr/sbin/gdm -- GNOME Display Manager