Merge pull request #4 from almossawi/master

Superficial changes to UI, first pass
Merge pull request #5 from almossawi/master

Added CSS changes
style tweaks
some CSS cleanup
minor linechart JS cleanup and tooltip injection revert
Aesthetic changes to UI, pass 2

* Crisp edges for y-axis grid
* 'Statistics' orange color updated with orange from style guide
* Added top margin to .bars
* Removed inset shadow
* Removed monotone interpolation
* Thicker paths
* Cleaner grids, removed axes, fewer x-axis labels, x-axis labels no
longer rotated
* 'Update' button label changed to 'Apply'
* Formatted numbers in tooltips (e.g. 1000 -> 1,000)
* Hovering on a series name in the legend dims the other series rather
than thickening the selected path
* Removed 'Total' from chart names since it seemed unnecessary
* Replaced logo with one resized using "bicubic sharper" since the
in-browser resampling was making it look fuzzy in Firefox (it was fine
in Chrome)
Added spaces after colons per note
Alphabetized descriptors
Replaced gradient with css gradient, updated styles per noted guidelines, added L10n comments
Used mixins for gradients, used existing clearfix class, alphabetized rules, added spaces after colons where they were missing
Removed commented line, which I believe is what the note is about.
Readded mouseovers on transparent circles following rebase
Merge branch 'master' of https://github.com/almossawi/marketplace-stats