v0.5 release

What’s new in Lively v0.5.0.0:
• Youtube.com & other video platform streaming wallpaper support.
Instruction on how to set it up: https://github.com/rocksdanister/lively/wiki/Youtube-Wallpaper
• Lively themes, new light & dark themes in settings. (applications will auto restart to apply the new theme)
• Mpv player support for video wallpaper, use this if you experience issues with the other video players.
Instructions: https://github.com/rocksdanister/lively/wiki/Video-Guide
• New Audio setting: Other Application Focused, continue audio playback when other applications are open (except when wallpaper playback is paused)
• Multimonitor: Duplicate wallpaper mode, sets the same wallpaper across all screens simultaneously.
• Transparency slider.
• Application wallpaper audio mute option.

Fixes:
• Fixed some crashes in Wallpaper Creator.
• Fixed crash when launching app type wallpaper that exits unexpectedly before gui is ready.

Other:
• Preview gif & Image are now optional in Wallpaper Creator.

first release.

Merge pull request #1 from rocksdanister/dev-build

release.