0.5.0 - Improved input and error handling

New features

• Improved input handling (input.ifPressed, input.ifHeld, input.ifReleased, ifXDirPressed etc)
• Assert macro arguments at assemble-time to fail fast and provide user-friendly messages
• Various optimisations
• Adds smslib-zest.asm helper for integration with Zest projects

Breaking changes

• The user overridable setting .defines are now capitalised for consistency with others consts (values that are only set once)
• interrupts.handleVBlank and interrupts.handleHBlank renamed to interrupts.ENABLE_VBLANK and interrupts.ENABLE_HBLANK