Ipv6 support (#231)

* Basic IPv6 support

Still missing: manual connection, QR-Code support needs to be changed to accomodate both IP versions (preferrably without breaking existing support

* Add manual connection with IPv6 addresses

This adds the ability to connect be connected from IPv6 addresses.
This also fixes the way IP addresses are validated on input.

Still currently broken: QR code connection

* Added IPv6 to QR code connection

On devices with support for IPv4 (example: 192.168.1.10) and IPv6 (example: 2a02::1), the code will look like this:
warpinator://192.168.1.10:42001/ipv6=2a02%3A%3A1 (%3A is ':')

On devices that only do IPv6 but not IPv4, the IPv6 address will be used for the host part in the QR code url:
warpinator://[2a02::1]:42001 (brackets indicate IPv6)

* Split shown data for manual connection into two lines

This splits the shown data for manual connection into two lines, one of which contains the data for IPv4 conenction, the other shows the one for IPv6.

Ipv6 support (#231)

* Basic IPv6 support

Still missing: manual connection, QR-Code support needs to be changed to accomodate both IP versions (preferrably without breaking existing support

* Add manual connection with IPv6 addresses

This adds the ability to connect be connected from IPv6 addresses.
This also fixes the way IP addresses are validated on input.

Still currently broken: QR code connection

* Added IPv6 to QR code connection

On devices with support for IPv4 (example: 192.168.1.10) and IPv6 (example: 2a02::1), the code will look like this:
warpinator://192.168.1.10:42001/ipv6=2a02%3A%3A1 (%3A is ':')

On devices that only do IPv6 but not IPv4, the IPv6 address will be used for the host part in the QR code url:
warpinator://[2a02::1]:42001 (brackets indicate IPv6)

* Split shown data for manual connection into two lines

This splits the shown data for manual connection into two lines, one of which contains the data for IPv4 conenction, the other shows the one for IPv6.

Update README.md

appdata: Update to follow the latest Flathub guidelines.

- New screenshots
- Shorten summary
- Improve description
- Bump oars version
- Clean up xml file layout

Update deb build, readme, dependencies, .gitignore.