AM-53 : Improve error management when central catalog is unreadable
AM-29 : [AM_LIST_08] add-on.(sh|bat) list --installed
Simplify Add-on class (remove defaults)
Fix missing fields in JSON serialization
Add more controls (URLs validation) in JSON parsing
Fix status directory path
Use Aether to sort add ons per versions
AM-30 : [AM_LIST_09] addon.(sh|bat) list --outdated