Begin Installation docs

-create Installation Instructions doc
-list requirements (needs to be filled out further)

-small wording changes in the quick install/extraction section
-note that the config file needs to be copied from the sample

-extracting done with note on which files have hardcoded paths
-mysql DB: note which files have creds hard coded

INSTALL.md: table of contents using doctoc

in the web server setup section of the docs, I reference the webconfigs
directory which I plan on creating with sample web server configs,
webconfigs/

INSTALL.md: needs pear Image_GraphViz

note that we need pear’s Image_GraphViz for visualizing AS relationships

add a CONTRIBUTING.md file