0.10.0

Lots of goodies in this release! I'm working hard on the 1.0.0
Roadmap, so things are changing
pretty quick, and I thought it would be nice to release this checkpoint.

Bug Fixes

• protocol: keep the owned spans (49151bb0)

Features/Breaking Changes

• derive: Allow anything Clone + Into to be used as a Span (385171eb)
• offsets:
  • nice utility function to get an offset from a Rust callsite (26f409c5)
  • utility function for converting from line/col to offset (75c23127)
  • more utility From impls for SourceSpan (95200366)
• protocol:
  • add Source impls for Cow and Arc (53074d34)
  • reference-based DiagnosticReport! (f390520b)