Fix a bug where include file `networking/services.subr' was not being
properly clustered.

Change `fixedsize' to `fixedsize = true' to satisfy newer versions of dot(1)
generating error "Warning: <stdin>: syntax error in line 27 near ','".

Remove bounding cluster surrounding various include-groupings, allowing
groups of include files to float freely to the greatest consumer (reducing
the density of rendered diagrams).

While here, change the bgcolor of include clusters from white to X11 color
`thistle' (a light purple).

Also, add the word "Subroutines" after include cluster labels.

Do not terminate the digraph definition with a semi-colon [;] after the
ending brace to satisfy newer versions of dot(1) generating error "Warning:
<stdin>: syntax error in line 940 near ';'".

MFC after:	3 days
X-MFC-to:	stable/10, stable/9