update README.
set basic files for presto support.
add presto datasource. add htaccess file for development.
use correct content type http header.
add prestoTargetCtrl.
Datasource for Presto database.
custom fields for presto datasource.
modify to add presto aggrestion functions.
add presto function editor.
presto function editor js file.
add approx_percentile aggregation function.
use moment to automatically set 'pseudonow' parameter if it is not available. set 'now' string from 'pseudonow'.
automatically set SinceDate.
Merge remote-tracking branch 'upstream/master'
Merge remote-tracking branch 'upstream/master'
use 'count' as default function instead of 'mean'.
Better pseudoNow mechanism. Now it uses pseudoNow as current time on web ui too.
Add configuration to indicate whether the time field in db is string type or not.
Then decide whether to parse date string or not before manipulate it as datetime.
enabling groupBy function for Presto datasource.
Merge remote-tracking branch 'upstream/master'