Merge pull request #536 from jamadam/master

fix for v4.40 test failure on older perls
updated Changes
improved documentation browser to be a little more RESTful
show how to generate absolute URLs
more tests for documentation browser
negotiate content for documentation browser slightly more strict
added a few Mojo::URL examples
more Mojo::URL examples
slurp and spurt work with bytes
small optimization
documentation tweaks
added experimental validation support
return collections with errors
added validation support to form helpers
documentation tweaks
added is_submitted method to Mojolicious::Validator::Validation
renamed is_submitted to has_data
renamed has_errors to has_error
fixed a few test descriptions
added regex check