Portable App Data Persistence

• For portable apps, they may have a portable-data directory in the app directory, used to store portable data.
• However, abyss still uses Link to link the standard data directory to ensure the consistency of the directory structure in $persist_dir.
  • C:\Users\<username>\AppData\Roaming\xxx
  • C:\Users\<username>\AppData\Local\xxx
  • C:\Users\<username>\Documents\xxx
  • C:\Users\<username>\xxx
  • ...
• If the standard data directory is no longer available, it should use Persist to replicate the standard directory structure.
• Refer to RealWorldGraphics.RWCursorEditor for the definition.