Allow configuring multiple wifi networks using wpa_supplicant (#250)

* use wpa_supplicant to configure wifi

* filename change octopi-network.txt -> octopi-ethernet.txt since it only configures ethernet now

* better format

* revert 22ec5ac 13e3fc1 ff3f351

* Only add /boot/octopi-wifi.txt, symlinked to /etc/wpa_supplicant/wpa_supplicant.conf, without breaking existing /boot/octopi-network.txt mechanism

* clear documentation for distinctions between octopi-network.txt and octopi-wifi.txt

* Change name /boot/octopi-wifi.txt -> /boot/octopi-wpa-supplicant.txt to avoid confusion

src/chroot_script

@@ -212,6 +212,26 @@ echo "mapping wlan1" >> /etc/network/interfaces
 echo "  script /root/bin/map_iface" >> /etc/network/interfaces
 echo "source /boot/octopi-network.txt" >> /etc/network/interfaces
 
+# allow configuring multiple wifi networks via /boot/octopi-wpa-supplicant.txt
+mv /etc/wpa_supplicant/wpa_supplicant.conf /boot/octopi-wpa-supplicant.txt
+ln -s /boot/octopi-wpa-supplicant.txt /etc/wpa_supplicant/wpa_supplicant.conf
+cat <<EOT >> /etc/wpa_supplicant/wpa_supplicant.conf
+
+# This is only used to configure multiple wifi networks or other advanced wifi features.
+# take a look into octopi-network.txt instead if you only need basic wifi configuration
+# 'man -s 5 wpa_supplicant.conf' for advanced options
+#network={
+#  ssid="Your Wifi SSID"
+#  psk="supersecretwifipassword"
+#}
+
+## You can configure more than 1 wifi networks by adding more 'network' blocks
+#network={
+#  ssid="Another Wifi"
+#  psk="password"
+#}
+EOT
+
 # copy /etc/wpa_supplicant/ifupdown.sh to /etc/ifplugd/action.d/ifupdown - for wlan auto reconnect
 [ -f /etc/ifplugd/action.d/ifupdown ] && mv /etc/ifplugd/action.d/ifupdown /etc/ifplugd/action.d/ifupdown.original
 [ -f /etc/wpa_supplicant/ifupdown.sh ] && ln -s /etc/wpa_supplicant/ifupdown.sh /etc/ifplugd/action.d/ifupdown

src/filesystem/boot/octopi-network.txt

@@ -9,6 +9,8 @@
 #
 # Just uncomment the lines prefixed with a single # of the configuration
 # that matches your wifi setup and fill in SSID and passphrase.
+#
+# If you need to configure more than 1 wifi networks, please use /boot/octopi-wpa-supplicant.txt instead
 
 ## WPA/WPA2 secured
 #iface wlan0-octopi inet manual