move poll.[ch] out of compat/win32/ into compat/poll/ and adjust
Makefile with the changed paths. Adding comments to Makefile about
how/when to enable it and add logic for this
Signed-off-by: Joachim Schmitz <jojo@schmitz-digital.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
