0.29.0b1

What's new (since 0.28.4):

• core/device: The firmware_auto_update attribute is now cached.
• core/expressions: Self port values are now treated differently than own port dependencies.
• core/expressions: Added support for minute/our/day/month/year time change dependencies.
• core/expressions: Many code and tests cleanups and reorganizations.
• core/expressions: Time-related functions are no longer recognized by transform expressions.
• core/expressions: Improved performance for various time-related functions.
• docker: Added support for /data/user directory.
• frontend: Improved unusable UI while updating many ports at once.
• frontend/ports: Virtual & writable ports are now visually indicated with a badge.