setup.py: Add 'mercurial' as include dir for the inotify compiler.
This patch adds access to util.h for the inotify C module by adding the
"mercurial" directory as an include dir, enabling access to the macros defined
in util.h.
% status without inotify
A a
! b
% inserve
% status
A a
! b
? hg.pid
Are we able to kill the service? if not, the service died on some error