…ession, channel and scp modules, updated tests.

Added non-blocking session connection/authentication and channel read tests.
Added helper function for doing socket select for testing non-blocking mode.

…ssl 1.1.x on windows.

Updated libssh cython definitions for windows compatibility.

…case.

…atibility.

…for linux and windows libssh builds.

…n dealloc.

Updated manylinux to 2010, updated manylinux dockerfile. Bumped manylinux libssh version.