GetFeatureInfoMenu Popup Fix

Close feature info popups when you switch between menu options. Fixes #178 issue.
WMS Feature info plugin changes.

* Dependencies gxp/FeatureEditorGrid.js, gxp/FormFieldHelp.js and gxp/SchemaAnnotations.js has been added.
* Feature popup can be displayed as feature 'grid' or as common 'html' changing format parameter.
* Fixes incorrect popup error with multiple layers
* Popup anchor fixes #91 issue
OpenLayer upgrade to v2.13.1
Merge branch 'olupmerge' of https://github.com/tdipisa/mapstore into olupmerge