Blacklist implicit packages for modulefile generation (#2603)

Add the ability to the modules generation process to blacklist
packages that were installed implicitly.  One can still whitelist
modules that were installed implicitly.

This changes adds a `blacklist_implicts` boolean as a peer to the
`whitelist` and `blacklist` arrays, e.g.:

```
modules:
  enable::
    - lmod
  lmod:
    whitelist:
      - 'lua'
      - 'py-setuptools'
    blacklist:
      -  '%gcc@4.8.3'
    blacklist_implicits: True
```

It adds a small helper in `spec.py` and then touches up the package
filtering code in `modules.py`.

0 files changed, 0 insertions, 0 deletions