Ignore DS_Store files
Ignore .DS_Store files
Ignore .DS_Store files
Moving toward a web interface

Also changed is-valid? in calc.clj to make it portable.
Moving towards Clojurescript
Removed :gen-class for portability
Working webpage mode

Several changes to get the webpage solver.html to work.
Ignore the /out folder
Ignore auto-generated /repl folder
Ignore compiled JavaScript (.js) files