Scratchabit

- Added menus support using picotui 0.8, all commands are exposed via menus.
- Switched dialogs to picotui (better and more consistent look and feel).
- More precise cursor positioning for "Search text" command.
- Add support for command line arguments --script (run script/plugin on startup) and --save (run script fully in batch mode, don't go to UI).
- Save format change: information now saves split per memory area (more friendly for human reviewer and git, potentially allows to reuse information for same memory area in different projects). Old save format is recognized and upgraded.
- Many small improvements to user experience (better progress indication, terminal deinitialization, avoiding overwriting comments from different stages of loading process, etc.)

- "Make filler" command, allowing to mark undefined bytes as unimportant filler.
- "Next undefined" command. Together with "Make filler" allows to follow reductionistic workflow, where a user searches for next undefined byte sequence and categorizes it (or skips for now, easily findable later).
- ELF loader: Fix loading of executable with REL relocations (e.g. x86) and generalize to easier support architecture-specific features.
- Number of minor UX improvements.
- Continue switching to picotui widget set.

- New commands: "Show address map", "Save listing for the current function", etc.
- Save viewer address stack on quit/load on restart.
- Add "default plugins" map, for more automatic loading of bare executables. Add Xtensa plugin to this map.
- Various small UI improvements.
- Better handling of disassembly of objects.
- Engine: clean up handling of "offset" operands.
- Detailed changelog: https://github.com/pfalcon/ScratchABit/compare/v1.0...v1.1

- Switched to picotui (https://github.com/pfalcon/picotui) for widgets, enabling better and easier to maintain UI
- Write disassembly listing to a file command ("W")

- Switched to YAML-based format for database

- Improvements to robustness and error handling