Adds dialog with info about export import
Removes html code from msg
Puts all in one string
Merge pull request #400 from doleiynyk/2014-01-03_Add_dialog_to_export_import

Adds dialog in admin interface with hints about the export and import
Adds Facebook link
Merge https://github.com/Arcavias/arcavias-core
Streamlines error messages and PayPal Express provider
Updates translation files from Transifex
Improves release target in phing file