Added more complete jshint options

https://github.com/JedWatson/keystone/issues/333#issuecomment-43159223
Clearer editorconfig definition around indentation

Not all editors have auto-detection enabled, so good to have the expectations clearly defined, those expectations being:

- tabs by default
- 2 spaces for json (npm really dislikes anything else)
Add coverage report and default gulp task.
Implemented #346

Changes:

- Linted `lib/list.js` and `public/js/view/list.js`
- Added between filtering to date, datetime, money, and number field
types
- Added some utility styles provided by @jossmac
- Removed trailing whitespaces for modified files
- Simplified logic for parsing list field input values and generating a
query string from them
- Simplified logic for generating queries from filters a little bit,
simplified a little bit for location

Tested:

- That filters correctly pass and fail for numbers and dates
- Have not tested changes yet on location, money, and date time fields
that were also touched by the optimisations
Fixed some regressions

- Fixes address query string not being generated correctly
- Fixed spacing issue with header items (due to trailing whitespace
removal)
Merge pull request #362 from balupton/issue-346

Implemented #346
Implemented and documented color field type
fixed space consistency
added missing semi-colons
Add code comments to View Class
Merge pull request #368 from LegitTalon/comments

Add code comments to View Class
Merge pull request #355 from balupton/patch-1

Added more complete jshint options
Merge pull request #356 from balupton/patch-2

Clearer editorconfig definition around indentation
Merge pull request #361 from jamlen/coverage

Add coverage report and default gulp task.
Merge pull request #366 from fbeaudet/color-field-feature

Implemented and documented color field type