Auto-check for update

[xtremexp]

• In program settings add a parameter to check for updates at start
• Modify "check for updates" menu so it if there is no newer version displays a message "No new update"
  else display a confirm message to browse to github release page.
• When program checks for update, send a request to github api comparing "name" (e.g: "1.1.1") with current version.
• If a newer version is detected open the github release page.

https://api.github.com/repos/xtremexp/UT4X-Converter/releases/latest
Returns:

  "tag_name": "v1.1.1",
  "target_commitish": "master",
  "name": "1.1.1",
  "draft": false,
  "prerelease": false,

In future version, maybe autodownload the latest release, execute installation program and close converter.