Accept multiple programs in bsd.prog.mk and remove bsd.progs.mk

[bapt]

Summary

bsd.progs.mk is wrong in many places. and for example install multiple times the
same things.

Instread turn bsd.prog.mk into a multiprogram version which:
1/ is compatible with the usual way of single programs
2/ Allow per program manpage definitions (simplifying conditional knobs on

program if needed)

3/ Allow per program bindir

All CFLAGS and CXXFLAGS are shared among programs (impossible to make per
program flags in my opinion it is not a big issue as not wildly used.)
DPADD/LDADD/LIBADD are shared accross programs
specific DPADD.prog LDADD.prog can be specified

BINDIR is shared among programs but can be overwritten per program
DEBUGDIR is shared and automatically built as before, but can be overwritten per
program

[bapt]

Note that I haven't yet tested a full build (just locale testing) but I would like to get an initiale review on the direction before going further

[imp]

This looks generally good. I haven't nit-picked it since most of the nits are pre-existing conditions. Other than the horrible BINDIR thing, I resisted...

share/mk/bsd.prog.mk

71

What's going on with this bit of nonsense then?

I know it isn't part of this change, but I'd like to understand it...

[bdrewery]

Are you going to commit this?

[bapt]

Not in this state it is broken by the fact that I cannot specify cflags/ldflags per prog and I have no idea how to fix that yet

[bapt]

@bdrewery's rP288158 should have fixed bsd.progs.mk