boot: cold-boot optimisations cutting bbctrl listen by ~8s on the Pi

- scripts/rc.local.fast: minimal rc.local that defers the heavy bits.
- scripts/bbserial-rebind.service: oneshot unit that unbinds ttyAMA0
  from pl011 and (re)loads bbserial before bbctrl.service.
- scripts/bbctrl.service: declare the After/Wants on bbserial-rebind
  so we can rely on it rather than racing rc.local.
- scripts/install.sh: ship the cold-boot bits with firmware updates
  (mask sysstat, replace dphys-swapfile with an fstab swap entry).
- scripts/rc.local + setup_rpi.sh + setup.py: wire updated paths.

setup.py

@@ -17,7 +17,7 @@ setup(
     license = pkg['license'],
     url = pkg['homepage'],
     package_dir = {'': 'src/py'},
-    packages = ['bbctrl', 'inevent', 'lcd', 'camotics','iw_parse'],
+    packages = ['bbctrl', 'inevent', 'lcd', 'camotics', 'iw_parse'],
     include_package_data = True,
     entry_points = {
         'console_scripts': [