Release v0.3.1

Fixes

• The parser/unparser.go appropriately handles space-sensitive operators.
• The interpreter/planner.go supports the overloading operations by overload id.
• Support for wrapper, protobuf.Any, and Proto3 to JSON-based protobuf.Value conversions
  within ConvertToNative.
• Support for iterating over the interpreter/evalstate.go values.
• Removed a pathological recursion case from the type-checker.

Release v0.3.0

Features

• Protobuf wrapper type support.
• The cel.AstToString helper to decode from ASTs to human readable expressions.
• Performance optimizations to treat list literals as sets when used with in operations.

Fixes

• Byte literals no longer be tied to UTF-8 codepoints.
• Type resolution fix for null assignable to null
• Type join fix for parameterized function argument types.
• Better handling for panics and concurrent execution.

Breaking Changes

• cel.OptFoldConstants eval option has been renamed to cel.OptOptimize