RR: WIP chart view
RR: add get chart fields for dataset
RR: add get chart for field in dataset
Merge branch 'master' into 9-charts-view
Merge branch 'master' into 9-charts-view
RR: get chart data as JSON
RR: WIP generate bar chart
RR: WIP try example chart
RR: display chart data
Merge branch 'master' into 9-charts-view

Conflicts:
	src/clj/ona/viewer/templates/datasets.clj
	src/clj/ona/viewer/views/datasets.clj
RR: fix error for empty maps (charts without data)
RR: private function for field-name query field
PLD: move chart gen from template to view
PLD: use parition over apply hash
Merge pull request #169 from onaio/9-charts-view

Basic Charts view