Remove aux files `config.{guess,sub}` and `install-sh`

These automake aux files are not needed (anymore).

Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>
Remove redundant `MIN_VERSION_unix(2,5,0)` conditionals

Since ad1a5c88 `process` supports GHC>=7.2 (which implies `unix>=2.5`),
therefore `MIN_VERSION_unix(2,5,0)` is always true.

Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>
Remove obsolete Hugs CPP conditionals in `Internals.hs`

The Hugs CPP conditionals in `System.Process.Internals` make little
sense, as that module is only listed in `exposed-modules` when
`impl(ghc)` and moreover, it's `import` in `System.Process` is guarded
by an `#ifndef __HUGS__`.

Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>
`M-x delete-trailing-whitespace`

Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>
Drop obsolete `if !impl(nhc98)` and refactor `.cabal`

This is a follow-up to e5fc2ac7c which removed NHC98 support but didn't
consider the `process.cabal` file. While at it, this normalizes other
parts of the cabal file and adds a `repository this` declaration.

Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>
Add `README.md` and `.travis.yml` script

This enables testing (or rather testing the packages builds) for all
released GHC versions this package is supposed to work with.

Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>