Fix an NPE thrown when the user dropped a source from the geocatalog on the map
Adds a close after the open so that the needed DataSource is
instanciated and we're still sure we won't have less calls to close than
calls to open because of this method.
We're not really checking that edid is open. we want to know if its datasource is null or not.
Change default step in spinning fields. We know have a constant for that.
Fix #363 by ignoring whitespace characters.
Fix text descriptions.

I just made a few changes to the English.
Just trim() instead of replacing *all* whitespace.

Thanks @agueganno
Add trim for jar URIs as well
Merge pull request #417 from agueganno/fix-414

About 414 - NPE when dragging a source on the Map.
Merge pull request #418 from agueganno/spinning-step-393

Change default step in spinning fields. We know have a constant for that.
Merge pull request #419 from agouge/fix/#363

Fix #363 by ignoring whitespace characters.
Encode whitespaces as %20.
Update help messages
Rename plug-ins --> plugins
Rename plug-ins --> plugins, take 2.
Merge pull request #420 from agouge/fix/encode-whitespaces

Encode whitespaces as %20 in the Add Plugin dialogs
Make a copy of list before iterating over
About #417
Improving a bit the strategy used to decide what the default symbolizer shall be
Add comment to explain modification.
improving javadoc