Too many libgfortrans

My situation:

I had a environment up and running, all was well

I needed fortran

I installed the gcc package to get gfortran.

all was well.

BUT ......

It turns out that that gave me a gcc as well, that kinda contaminated the rest of my system, so I had to remove it.

But now numpy is broken:

```
---> 14 from . import multiarray
15 for envkey in env_added:
16 del os.environ[envkey]

ImportError: dlopen(/Users/chris.barker/miniconda2/lib/python2.7/site-packages/numpy/core/multiarray.so, 2): Library not loaded: @rpath/./libgfortran.3.dylib
Referenced from: /Users/chris.barker/miniconda2/lib/libopenblasp-r0.2.18.dylib
Reason: image not found
```

So I am making an educated guess that numpy depends on openblas, which requires libgfortran, and apparently installs it itself.

gcc also install the same lib. -- so when I remove gcc, I break gfortran.

Ideally, conda would do some kind of reference counting or something, so that it wouldn't remove a file that another package is also using -- but that's a major feature that may never come.

So: shouldn't libgfortran (and similar) be a package by itself, and then gcc and openblas, and who knows what can depend on it?

Also nice for gfortran to be separate from gcc as well...