win32: specify _CREATE_NO_WINDOW on spawndetached() Before this change, a console window briefly popped up on "hg serve -d" and disappeared again, stealing the focus window (which was very annyoing when running tests). Specifying _CREATE_NO_WINDOW instead of _DETACHED_PROCESS fixes this (as tested on Windows 7 x64).

amend: disable hooks when creating intermediate commit (issue3501)