Description of problem:
The manual referred to in the OMF file has an incorrect URL, so it can't be
opened in yelp.

Version-Release number of selected component (if applicable):
1.7-1.fc6
1.7-2.fc7
(might want to check fc5 as well, didn't have a host handy)

How reproducible:
Every time

Steps to Reproduce:
1. Open yelp (F1)
2. Select "Programming" from listing on left
3. Select "GTK-Doc Manual"
  
Actual results:
URL is incorrect

Expected results:
Visible documentation

Additional info:
I'm attaching a patch that I think is OK.  I'm not sure why the
help/manual/C/Makefile.in refers to $(docdir) since it's not set as far as I can
tell.  Instead, the rest of the Makefile.in's are using $(gtkdochelpdir).  Sorry
if this is disingenuous, as I am a neophyte when it comes to autotools type stuff.