When using relative directories, or no directories, in
the include file list, it works the first time a CHM
generation is done.
But because the current directory is changed to call
HHC.exe, the second time it does not work.
The attached fix will ensure that if a file type is not
found, it tries again with the path to the
delphicodetodoc project file (XML) added in front.
This allows effective use of relative paths in the
include file list.