added FiveAM, asdf:test-system etc
viz fix. less effort to understand and start using the library
documentation: api, readme...
copy-and-paste code of shadowing-import
added a tutorial
updated readme: mentioned the tutorial
it is awkward to run a test each time vizualizer is invoked.
Merge pull request #1 from guicho271828/fiveam

added FiveAM, asdf:test-system etc