Improvements for basic templates (viewer, composer)
Service Box widgets improvements.

Changes on widgets:

* PrintSnapshot
* KMLFileUploadPanel
* MapFileUploadPanel

in order to include the error log from servicebox.

Also include:

* PrintSnapshot --> Add SERVICE=WMS to the request URL.
* MapFileDownloadPanel --> Hide load mask when the request fails.

This changes and the geosolutions-it/servicebox#5 pull request fixes #138 issue.
Merge pull request #302 from alediator/issue_138_servicebox_improvements

Service Box widgets improvements.
Merge branch 'master' of https://github.com/geosolutions-it/mapstore into ckan
Merge pull request #305 from tdipisa/ckan

Improvements for the URL params managements in viewer and composer
#305, small refinements to the preview configuration.
GetFeatureInfo settings. Close #160.
Fix the poweredby URL. Close #309.
#152, Refined the servicebox configurations for the ant release
#305, enabled layer chooser.
#305, Using OSM as default background in preview config