Refactor layout

[weaverba137]

This PR:

• Closes #11.
• Allows installation via a simple git clone command.
• Adds the Jupyter init scripts to the package.
• Implementation will involve changes the path to the DESI environment and Jupyter init scripts, so documentation will need to be updated to reflect that.
• Internally, module files and init scripts still use the /global/common/${NERSC_HOST}/contrib/desi path. This would allow this PR to be "dropped in" right now, rather than waiting for a subsequent release that uses the /global/common/software path.

[weaverba137]

I'm still thinking about what to do about the scripts. Currently we have the scripts in one place (desi/software), but with this branch, as-is, there would be multiple copies of the scripts. So, for example

source /global/project/projectdirs/desi/software/desi_environment.sh 17.12

would become

source /global/common/software/desi/${NERSC_HOST}/desiconda/startup/modulefiles/desimodules/desi_environment.sh 17.12

I'm currently thinking of restoring a Makefile that would install the scripts in /global/common/software/desi, so that you could do

source /global/common/software/desi/desi_environment.sh 17.12

which looks much cleaner.

[sbailey]

I definitely prefer the shorter cleaner path; could we just continue to use the current /project/projectdirs/desi/sofware/ location that many people are already using? Also seems ok if we just maintained that by hand, copying out of desimodules when needed. A Makefile seems like overkill.

[weaverba137]

How about keeping the files in desi/software but making them symlinks to, e.g. the edison version?

[weaverba137]

@sbailey, I have added the 18.2a updates to the master branch and tagged it. I still need to resolve some conflicts before this can be merged, but this will be ready soon.

[sbailey]

Fine with me; merge when ready.

[weaverba137]

Conflicts resolved, but if I can quickly get answers to #15 & #16, I can get those in as well.