table header moved to dc.js

Still allows original example to function as-is.
Allows non-hard-coded table column headers.
changed data-table to support dynamically set columns for table header

Supplied 3 examples of setting the columns; the original method, which
requires the fixed html code for thead/cols; another which uses mostly
the data element names which become capitalized as col headings, and
another where most of the columns have the column label specified along
with an accessor function. There is some code to strip a
numberFormat/etc from a function converted to string, an attempt to
auto-generate a column header from a function, in data-table.js,
columnString().
fixing unintended checkins
updated stock example via grunt
attempt again, renderedstockfixture
attempt3 after installing saucelab; touched data-table.js
retry 4. connected sauce
review changes

Restored index.html, no need for a change.
Added 4th example of columns.
updated restored stock example
added ValueFormat function

so both header and value can be overridden
Removed columnHelper fn

Changed to use just an in-line Object, and allow any Object
specification desired, with note to override the internal functions to
match.
I think this is the cleanest and most flexible version.
Incorporated feedback from PR #560 to alter Object formatting for columns and add jasmine tests
Merge PR #668
bring code in line with coding conventions

- break tests into describe(noun) it(verbs)
- indentation etc as mandated by jscs/jshint
- remove testing examples from stock.js and keep the most general one
- remove header from index.html because header is generated now