add an 'abort' method to abort istream operation from another thread.
You can pass request_content as a buffer ptr and length that WILL NOT be copied by the request_content object.  This avoid copying big buffer but user is responsible for keeping the memory around while the istream operation is in progress.
Support for web proxy with basic authentication.
add abort method on istream.
fix request_content fir using with a std::string
Merge pull request #1 from sandym/master

3 additions