Graph: improved decimal precision in legend and graph hover when graph ticks use single decimal point, now graph legend and tooltip always use one more decimal precision than axis ticks (if axis ticks has decimals), Fixes #1072

Graph: added export graph time series data as csv file feature, accessed from panel menu dropdown, #861

SinglestatPanel: Added integration with drilldown link feature, if a drilldown link is present the entire singlestat panel will act as a link, with hover tooltip containing the link name, #951, #1041

panelmeta: fix metrics tab title.

Graph: change to current legend value handling, if last value is null, current will pick next to last value, Closes #190

Graphite: fix for graphite query editor, when adding functions and the function selection dropdown get push down the selection did not work properly, Fixes #1038

SinglestatPanel: increased scaled decimal offset by 2 for, improves decimal precision when units gets scaled, #1043, #951