* Changes cancel_on_connection_lost default to false
* Deprecates cancel_on_connection_lost and cancel_if_not_connected
* Fixes a TODO in test_conn_exec_cancel
close#323
* Terminal cancellation in async_exec no longer tears down the connection when the cancelled request has been sent to the server.
* Adds support for partial cancellation in async_exec with the same semantics.
async_exec now supports partial and total cancellation when the request is pending
Added docs on async_exec's cancellation support
Added detail::exec_fsm and macros for coroutine emulation
Requests are now removed from the multiplexer when an error is encountered
Updates multiplexer to make requests complete with error_code() rather than error_code(0)
Integration tests now use io_context::run_for to run with a timeout and avoid deadlocks
Tests now use concrete lambdas where generic ones are not required
Tests now use BOOST_TEST with operator== to print values on error
Tests now use anonymous namespaces to detect dead code
Adds run_coroutine_test and removed start from common.hpp
Updates test_reconnect to perform relevant checks
Refactors how test_issue_50 launches its coroutines
Groups tests in CMake as unit or integration
Updates Jamfile tests to contain all unit tests and only unit tests
