Run selected text. Implements sosedoff/pgweb#78.
Run selected text. Implements sosedoff/pgweb#78.

In the Query tab, only run the selected text. If nothing selected, run all text in the editor.
xiongjungit/pgweb,akarki15/pgweb,hardware/pgweb,hardware/pgweb,sosedoff/pgweb,freeformz/pgweb,freeformz/pgweb,trigrass2/pgweb,adamjaso/pgweb,sosedoff/pgweb,beni55/pgweb,xiongjungit/pgweb,w4ngyi/pgweb,adamjaso/pgweb,sosedoff/pgweb,akarki15/pgweb,daveallie/pgweb,trigrass2/pgweb,beni55/pgweb,niiyz/pgweb,daveallie/pgweb,trigrass2/pgweb,w4ngyi/pgweb,beni55/pgweb,adamjaso/pgweb,xiongjungit/pgweb,niiyz/pgweb,xiongjungit/pgweb,freeformz/pgweb,adamjaso/pgweb,akarki15/pgweb,hardware/pgweb,trigrass2/pgweb,beni55/pgweb,niiyz/pgweb,freeformz/pgweb,akarki15/pgweb,niiyz/pgweb,w4ngyi/pgweb,w4ngyi/pgweb,daveallie/pgweb,daveallie/pgweb,hardware/pgweb,sosedoff/pgweb