code formatting

being more consistent with tabs vs. spaces.
universal function for changing innerHTML

should make code more succint and readable
universal func for setting/getting values

as above.  code changed to use this.
formatting

more spaces => tabs
also using calculator.get_el() instead of document.getElementById()
--> eventually all in an object to be this.get_el when condensed
properly.
moving CSS to <style>

where possible, and partial CSS consolidation
GA, reordering of code

as above
code cleanup

adding in comments, removing unused variables
Merge pull request #2 from sgazard/experimental

Experimental