Parsley 4.2.9

Minor bug fix for a couple of error related bugs:

• many keeps hints alive for longer than they need to, hints are now always discarded on the end of an iteration (I'm not sure why this behaviour was ever special cased to begin with, if anything weird now happens to errors as a result of this patch, let me know)
• trivial errors now cap the caret to line length
• hints cannot impact the unexpected width of an error if they themselves do not demand an unexpected token.

What's Changed

• Removed the type casts within the expr machinery by @j-mie6 in #173
• Fixed various error bugs by @j-mie6 in #174

Full Changelog: v4.2.8...v4.2.9