added shutdown command for the full node to the UI's unload event

to close the underlying node, replaced the window.beforeunload event by an http request at electron level

Adding a keepalive endpoint that if enabled will shutdown the node after a trashold

Adding a shutdown api method

Rename smallestBlockHeightInWallet to earliestWalletHeight and added …

SyncManager now doesn't wait for the full chain to be downloaded but …

SyncManager now doesn't wait for the full chain to be downloaded but rather wait until we have enough data to start asking for blocks

Improve error handling

- Wait on API to load UI
- Add basic error handling to API calls

Spawn API when in production mode

Add server polling

Checking for segwit activation and adding the behavior to drop nodes …

Chain + loglevel

Fix Electron hard resets