perltidy

How much do we care about applying perltidy, as described in
src/tools/msvc/README, everywhere?  I just ran it across the entire
tree, using

perltidy -b -bl -nsfs -naws -l=100 -ole=unix **/*.pl **/*.pm

and it generated 6531 lines of (unified) diff, of which 357 are in
src/tools/msvc/ itself.  So clearly it's not being applied very
consistently.

Given how easily this appears to work and how we're sneakily expanding
the use of Perl, I think we ought to add this to the standard pgindent
routine.