Auto-refresh installed status of imported games from Steam

[Ben uno]

Since LaunchBox already reads the corresponing entries for installed Steam games once at startup it would be great to have an auto refresh function built in with a customizable poll-rate or event driven when external hard drives get is-/connected, games un-/installed.

[Christian]

We also do it when you return from LB after playing an installed Steam game, but I could see adding a manual refresh via the Option menu