[ohm] Cleanups

[Rob Taylor]

I've just pushed the first few of my cleanup patches, there's a patch to
fix building for the OpenEmbedded guys [1], some documentation cleanup
[2], some ohmd ABI chopping [3] and a large change that allows ohmd to
be run uninstalled [4]. Note that this last patch has a knock-on for
those of you working on new plugins, so please do look though the
changes to Makefile.am for the current plugins.

Thanks,
Rob Taylor

[1]
http://gitweb.freedesktop.org/?p=ohm.git;a=commit;h=0ba9447666489d97909ce61b5564a734b2da03dd
[2]
http://gitweb.freedesktop.org/?p=ohm.git;a=commit;h=3f979e84aaf1af9cc08e961581fc4f466250d8bc
[3]
http://gitweb.freedesktop.org/?p=ohm.git;a=commit;h=f22b791a479dcadf002277f4a5ed6c0955476016
[4]
http://gitweb.freedesktop.org/?p=ohm.git;a=commit;h=d1831df1b0c9eb8179601f873f9dbc80d021fbfe