Fix timezones in line chart

Ceilometer gives us UTC and works with UTC, we should honor that
in line chart, cause we are just passing samples there.

Hover detail of sample should show localized time.

Change-Id: I83c23a13eb27b71e71268bc7b99c0ce0fdd1d59a
Closes-Bug: #1359690
Only enable one images filter button

Only one button for the images filter buttons should be enabled at any one time.
This is solved by removing the active class from all the filter buttons upon
selecting a filter.

Change-Id: I9d7753684f144a6d66ccc5b09f830b360a07a620
Closes-bug: 1365803
Merge "Fix timezones in line chart"
Merge "Only enable one images filter button"