Raise error if a Message re-uses a field number.
test message equality and equality with non-messages
Make sure we compare same classes when checking for message equality
Merge pull request #52 from protobuf-ruby/bk-message-equality

Message equality testing is class-aware
bump version
take force_encoding as a standard feature
assume we always have ord to turn strings or integers into integers
assume the presence of bytesize and byteslice
remove unsupported rubies from travis
Merge branch 'master' into retailnext-field-reuse

Conflicts:
	test/message_test.rb
add tests for messages with fields named fields
support fields named _fields
Merge pull request #47 from protobuf-ruby/bk-remove-18

Deprecate old versions of Ruby
Merge pull request #54 from protobuf-ruby/retailnext-field-reuse

Throw an error if a Message tries to reuse a field number
call the instance method that lists fields __beefcake_fields__
Merge branch 'master' into bk-fields

Conflicts:
	test/message_test.rb
Speedup encodable check
Merge pull request #55 from eac/eac/speedup_encoding_check

Speedup encodable check
Merge pull request #35 from protobuf-ruby/bk-fields

Support fields named "fields"
Merge branch 'master' into add-ruby-prof

Conflicts:
	test/message_test.rb