Document miscellaneous maintenance items for site

[jluebeck]

• what to do if disk becomes full
• document start/stop for neo4j
• how to migrate amprepo to a new instance

[liefeld]

as part of this I am going to also make some code changes to reduce the disk space waste and automate cleaning it up

[liefeld]

Take a look at the neo4j section of the README.md file. I don't have anything to add to whats already there.

[jluebeck]

For Neo4j, we probably should indicate something in the start/stop server instructions to check if it is up and running, and if not to start it at that time. For instance if we have to restart the instance due to some AWS issue, it will be good to have Neo4j in our checklist.