Auto-update

[joelthe1]

Allows the app to read release information from GitHub and update existing application without needing to re-install. This should be explicitly enabled by the user and should be switched-off by default.

User flow:

1. If the app has auto-update enabled, it checks for update on app start or using a button within the auto-update section of the settings pop-up.
2. Once an update is available, it shows a pop-up with an option for the user to download it.
3. If the user agrees, the update happens in the background and the progress is shown in the top bar.
4. Once the update is downloaded, the user is shown a pop-up with the option of either installing it then or on app restart.
5. Either ways, once the app is updated, the user is shown the proof of the update in the top-bar via the new version number. (This assumes the app always shows the version number on the top bar).

• When the user enables the auto-update, it should have a confirmation pop-up with the title 'Confirm Internet Access' that says 'Enabling auto-update would allow Autographa Lite to connect to the internet to check for updates during the start of the application. Are you sure you want to proceed?' It should have options of 'OK' and 'Cancel'
• The Auto-update tab, when enabled, should have a link that says 'Check for updates now' and once clicked it should become 'Checking...'. Once the user allows the download, the link should change to 'Update downloading...'.
• If there is no update available, there should be a pop-up that says: 'Auto-update Unavailable' as title and and text: 'Autographa Lite is up to date.'
• The pop-up when update available should have title 'Autographa Lite Update Available' and the message should be 'A new version of the app is available. Do you want to download the update now? You may continue working while the update is downloaded in the background.' It should have options 'Download' and 'Cancel'
• When the user has finished downloading the update, there should be a pop-up shown with the title 'Install Updates' that says 'A newer version of Autographa Lite has finished downloading. Do you want to install the update now? Otherwise, the update would be installed when you restart the application.' It should have options, 'Install and Restart' and 'Later'.

[joelthe1]

• Add a way to re-use the DB when re-installing the app.