[tex-k] Newly introduced overfull line in tangle.pdf

[Andreas Scherer]

>> The deviation most likely comes from my 'pdfwebtocfront.tex' macros: 
>> github.com/ascherer/cwebbin/blob/master/texinputs/pdfwebtocfront.tex#L22
> No, it comes from my 'pwebmac.tex':
To be precise: The deviation comes from CWEB 3.0. ;o)

'pwebmac.tex' draws heavily on 'cwebmac.tex' for its PDF-creating 
capabilities and inherited a slightly different definition of macro '\N' 
compared to 'webmac.tex'. In the final line of that macro, after the 
'\bf' for the section number there's a missing '\ignorespaces' that's 
present in 'webmac.tex'.  Re-entering this fixes the overful hbox.

Comparing old versions of 'cwebmac.tex' reveals that CWEB 3.0 lost that 
particular '\ignorespaces' from CWEB 2.8 in June 1993; see this 
interesting glance into the history of programming: 
https://github.com/ascherer/cweb/commit/97c7ceaf50d1c6b631eccd44ee252a63db8d8d72#diff-a572bc4106e89bd46478ac80e4511bab1b9e70fa23f8f60d9225bfa09f82f14cL115

Line #117 in red' (CWEB 2.8) is significantly different from line '149 
in green' (CWEB 3.0), not only in the increased parameter number '#3', 
but also in the missing '\ignorespaces' -- for whatever reason.

I guess I'll fix 'pwebmac.tex' to make it consistent with 'webmac.tex'.

Happy C/WEB programming!
Andreas