Make query text area standalone js file

[LaurensRietveld]

Config js object should contain at least: { handlers/callbacks {

• prefix/property/class autocompletion: allows for pre-definining completion suggestions
• onQueryComplete }, setQuery setEndpoint setQueryParams / request headers / request method / etc getQuery: (get text field value) executeQuery: returns error or result proxy (optional: if defined, will use this proxy to query cors-disabled endpoints) tracking: e.g. google analytics or piwik }

[LaurensRietveld]

done (see http://yasqe.yasgui.org)