Changed WiFi connection detection to Event Based Listener

[3ygun]

What?

Following the https://stackoverflow.com/questions/1783117/network-listener-android and https://developer.android.com/reference/android/net/ConnectivityManager.html I changed from the custom WiFi ready code to an event listener one. Appears to work tested turning on and off the WiFi on my phone and the app didn't crash and was able to resume calculations. Also seems to resolve #24

Parts

NOTE: DO NOT MERGE UNTIL THE FOLLOWING ARE COMPLETE

• [x] Remove old wifi code
• [x] Refractor out new code?

Fixes

• [x] #25
• [x] #24
• [x] #15 -- How should I test this?

[tylermzeller]

Confirmed memory leak fix?

Since you removed NetworkUtils, #15 shouldn't be an issue. Just test a few experiments to ensure the wifi connectivity is reliable and quick to respond to a connectivity change.

[3ygun]

@tylermzeller I removed the WifiHandler thread also. Could you check through the changes and see if they work on your end. I can fix feedback and when done we can merge.

My Concerns

• Didn't know if I tested a full disconnect/onDestroy of the app and made sure it could recover
• I didn't add any destroy broadcastReciever code see if we want to add it