More pgindent tweaks

After I committed 1249371632 I thought that I should really go ahead and
do what I suggested and allow multiple exclude pattern files for
pgindent. One obvious case is to exclude an in tree meson build
directory. I also sometimes have other in tree objects I'd like to be
able exclude.

The attached adds this ability. It also unifies the logic for finding
the regular exclude pattern file and the typedefs file.

I took the opportunity to remove a badly thought out and dangerous
feature whereby the first non-option argument, if it's not a .c or .h
file, is taken as the typedefs file. That's particularly dangerous in a
situation where git is producing a list of files that have changed and
passing it on the command line to pgindent. I also removed a number of
extraneous blank lines.

cheers

andrew

--
Andrew Dunstan
EDB: https://www.enterprisedb.com