* Introduction of IXWebSocketSendData that makes it possible to not only send std::string but also std::vector<char/uint8_t> and char* without copying them to a std::string first.
Add a sendUtf8Text() method that doesn't check for invalid UTF-8 characters. The caller must guarantee that the string only contains valid UTF-8 characters.
* Updated usage.md: sendUtf8Text() and IXWebSocketSendData
* introduce send fragment
* can pass a fin frame
* can send messages which are a perfect multiple of the chunk size
* set fin only for last fragment
* cleanup
* last fragment should be of type CONTINUATION
* Add simple send and receive programs
* speedups receiving + better way to wait for thing
* receive speedup by using linked list of chunks instead of large array
* document bug
* use chunks to receive data
* trailing spaces
