- sometimes the session got lost (e.g. if you renamed the cookies and
probably if servers were switched or restarted) and authtkt_identity was
then None, so checking of drupal session prefix was not always possible

Users can like datasets. When pressing button in GUI a cookie with
package id is set and number of likes is increased if the user does
not have a cookie with package id.
A separated table for package likes is created to avoid updating the
whole dataset.

Fixes buttons and listeners after changing package type.
Disables saving url resources with different package type.

Fixes uploading files and adding files with URL.
Fixes copying of unsaved data on changing package type.
Adds listener for data change after posting package resource.
Unifies text on buttons for checking links.

And sets table column width before showing success or
error message to prevent jumping content.

fixed couple of bugs - resource_create not working through API and additional_resource redundantly set

Content editor can add resources to an active package.
Resources can also be deleted or updated.
Logic for switching between individual and timeseries resources
is fixed accordingly. If no resources are present there is no
constraint for switching.
If there are resources of one type and one would like to add
resources of another type, package must be sent in confirmation
to admin. If resources of first type are removed, resources of
another type can be added by content editor.
Individual resources can also have 'refresh interval' property.