grid view: display events timestamp in human-readable format

... as opposed to milliseconds since the epoch.
Merge pull request #39 from mfournier/display-human-readable-date-in-grid

grid view: display events timestamp in human-readable format
Document the :host option
Merge branch 'master' of github.com:aphyr/riemann-dash
Add options to the flot graph to allow building stacked graphs and bar graphs
Merge pull request #41 from Shopify/stacked_graphs

Add options to the flot graph to allow building stacked graphs and bar graphs
s/:host/:bind/

Sinatra uses `:bind` to specify the interface to bind to: http://www.sinatrarb.com/configuration.html#bind---server-hostname-or-ip-address
Merge pull request #42 from michaelfairley/patch-1

s/:host/:bind/
Optional server-sent-event connection type.
Merge pull request #43 from pyr/feature-sse

Optional server-sent-event connection type.
Version 0.2.6
Add .state.err and .state.warn strings
Merge pull request #44 from bmhatfield/additional-state-strings

Add .state.err and .state.warn strings
Revert "Allow expired events in the grid and style with phonecian purple"

This reverts commit a103a62faf27d3e1ac728bb12a001a0cf92e4a08. Users
complained that persistent expired events was not the right choice for
them.

Conflicts:
	lib/riemann/dash/public/views/grid.js
fix: expired values appear as 0. Now they appear as "null". Maybe this
should be "expired" instead?
Merge pull request #45 from ccin2p3/f/format-null

fix: expired values appear as 0