maint: consolidate several .gitignore files

Unlike .cvsignore under CVS, git allows for ignoring nested
names.  We weren't very consistent where new tests were
being ignored (some in .gitignore, some in tests/.gitignore),
and I found it easier to just consolidate everything.

* .gitignore: Subsume entries from subdirectories.
* daemon/.gitignore: Delete.
* docs/.gitignore: Likewise.
* docs/devhelp/.gitignore: Likewise.
* docs/html/.gitignore: Likewise.
* examples/dominfo/.gitignore: Likewise.
* examples/domsuspend/.gitignore: Likewise.
* examples/hellolibvirt/.gitignore: Likewise.
* examples/openauth/.gitignore: Likewise.
* examples/domain-events/events-c/.gitignore: Likewise.
* include/libvirt/.gitignore: Likewise.
* src/.gitignore: Likewise.
* src/esx/.gitignore: Likewise.
* tests/.gitignore: Likewise.
* tools/.gitignore: Likewise.

docs/devhelp/.gitignore

@@ -1,4 +0,0 @@
-Makefile
-Makefile.in
-libvirt.devhelp
-*.html