Frame: document "fin" field in the constructor and fin() accessor. to_bytes() now encodes "fin" bit according to the fin field of the Frame object.
Frame: POD update: ATTRIBUTES - type section is moved under new() method. This is way more straightforward.
Frame: add "continuation" frame type. opcode() method is revised so that it can correctly return 0 if $frame->{opcode} == 0.
Frame: now "type" field for new() is immediately resolved to opcode, so that new(type => $type) and is_{type} methods are now consistent. This fixes github issue vti/protocol-websocket#19 ($frame->{type} field is preserved for backward-compatibility, but direct assignment $frame->{type} = "close" followed by $frame->to_bytes() will not work anymore. However, direct assignment is considered rude anyway...)
Frame: add is_continuation() method.
Frame: add documentation about "opcode" field in new() method and opcode() accessor method. tests are also added.
Frame: remove fin() accessor from documentation and test. If a message is fragmented, the return value of fin() is meaningless anyway. Plus, probably current implementation does not handle fin flags if control frames are injected in non-control fragments. If we want fin() accessor, the test for that case is necessary.
Frame: add documentation of "masked" field in new() method.
Frame: add documentation of "version" field in new() method.
Frame: documentation: add remarks about destructiveness of append() method. Sometimes it's useful, the other times it's confusing.
Frame: add test for destructiveness of append() method.
Frame: add test in which Frame class generates and parses a series of fragments.
Merge pull request #20 from debug-ito/master

added interface and documentation to Frame class