Merging type definitions with rpm-rs

[madonuko]

The current state of rpmspec-rs is "good enough" as in it can be used in production to read preambles. With that in mind, we probably might want to start merging code between rpmspec-rs and rpm-rs.

Personally I think it makes more sense for rpmspec-rs to use the types defined in rpm-rs as obviously they have a larger userbase and less cargo dependencies. In that case, the following entries need to be merged:

• [ ] %changelog
  • [ ] ChangelogEntry (requires parsing implementation, current one is broken and unused)
  • [ ] Timestamp
• [ ] %files
  • [ ] FileEntry
  • [ ] FileOptions
  • [ ] FileVerifyFlags
  • [ ] FileMode
  • [ ] PackageFileEntry
• [ ] Package
• [ ] Nevra
• [ ] Evr
• [ ] Scriptlet
• [ ] Dependency
  • [ ] DependencyFlags

[dralley]

The File* APIs probably need some adjustment, since as it stands they are barely usable IMO. But hooking it up to specfile parsing is probably a great way to sort out the issues and figure out what needs to be done about them.