Release 0.4.0

Added

• bundle ssl for better cross distro compatibility #67
• embed assets for easier distribution #67
• use same font as Veloren #67
• option to retry if download/install failed #78
• offline support #87

Changed

• place screenshots, logs, game saves in profile #74
• do not close Veloren if airshipper gets closed #77
• prune log file automatically 87

Removed

• extra terminal window #67