libftdi1: new package

This is the 1.x version of libftdi, as opposed to our existing libftdi
0.20 package.

(AVRDUDE is an (optional) dependee of libftdi1.)
avrdude: rewrite expression

* Use stdenv.mkDerivation instead of composableDerivation.
  stdenv.mkDerivation is the current coding standard and is easier to
  read (IMHO).

* Remove the 'parportSupport' flag because it doesn't do anything.
  (Parallel port support is still enabled.)

* Remove unneeded --disable-dependency-tracking flag to ./configure; our
  default builder does that already.

* Fix documentation build. But it is still disabled (by default),
  because texLive is such a big dependency. There is always the man
  page.

* Update 'meta' attributes
avrdude: add extra dependencies: libelf, libftdi1, readline

They are strictly speaking optional, but they provide useful features...
avrdude: update 6.0.1 -> 6.1