Large re-organization to remove cyclic module dependency graph

[chrisdone]

Related to #187. The current master module hierarchy evolved organically with much sharing between files, making it a mess of a graph (see @hvr's picture). This pull request finally corrects that. Opening as a pull request because any changes you guys have committed locally will have to be rebased. So I suggest you push your changes first and I will rebase upon them. However, the longer this goes unmerged it will be harder to do so. I'm going to give it a grace period of a week before merging, although if everyone is happy to go ahead I'll merge it sooner.

I wrote a trivial script that would rm all .elc files and byte-compile just the file I wanted to test. Using that, I ran it on every file in the project to see that every file had the proper require dependencies. Naturally, the HIM modules were all an interloping mess, so I've significantly moved code around so that the hierachy fits. Here is the new hierarchy:

As you can see, at the top is the haskell module. Given that the haskell-mode.el module contains the mode, it didn't make sense to have everything being pulled into there, especially given that many things depend on haskell-mode.el itself. So we end up with three 'big' modules that are depended on a lot: haskell-mode.el, haskell-interactive-mode.el and haskell-process.el. I removed all the specialized commands and things from haskell-session, haskell-process and haskell-interactive-mode into haskell-load or haskell-commands. It makes those modules nice and small (relatively speaking). I would like to do further breaking down of that haskell.el file until it's nearly just a list of imports.

I didn't actually rename any functions, though I would've liked to (using make-obsolete), but that would be far more problematic. The point is to move things in the right files. It's not entirely finished, nor am I sold on the particular module naming, but I consider this a big step in the right direction. After this we can incrementally improve.

[purcell]

Looks really good to me, but I feel sorry for the #370 guy, because he's going to have to completely rework his PR (again) if it doesn't get merged before this one. Would it be a pain for you to integrate his changes?

[chrisdone]

It looks like his PR is mergeable at this point? I'm not a Nix user so I can't confirm it. At any rate I don't intend on making anyone else re-do work.

[purcell]

Yes, I'd consider it basically mergeable, but have reservations about the hack to install el-mock. If it's okay with you (at least for now), then we can go ahead.

[chrisdone]

Agreed, last time someone added Cask to one of my repositories I never finished getting it to install and have never used it since. Let's merge without the tests and move that elsewhere.

[chrisdone]

Grace period over. Merged!

[purcell]

Great job!

[gracjan]

@chrisdone: Is your module-refac branch still needed or can we remove it?