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
Merge pull request #424 from agueganno/default-symbolizer

Change the strategy used to decide what the default symbolizer shall be.

Fixes #422.
Merge pull request #423 from nicolas-f/fix/concurrent-modif

Make a copy of list before iterating over it.

Fixes #421. See also #417.