Don't immediately run links added to an Event/AsyncResult while it is running callbacks. Fixes #771.

Make the forewarn about 2.6 a permanant part of the readme that ends up on PyPi. It's not necessary to change whatsnew_1_1 in this branch, as RTD deploys from master. [skip ci]

Issue some warnings for patch_all with invalid parameters

Update socket docs to clarify their duplication of stdlib interface; tone down the warnings. [skip ci]

See changelog.rst for details.

Also skip the 'make' step on Windows if installing from an sdist (piggyback the Unix method of looking for Makefile/Makefile.ext). Ref #757.

Notes about cython on windows. XXX: Duplicated a couple places, intro.rst and README.rst, we should refactor.