[CDE-219] Add the ability to hide arbitrary folders from the system file picker
	- folder hiding in file picker only occurs for non-admin users;
	- cde-pentaho / cde-pentaho5 's settings.xml now offers a tag where users can set a list of directories they would like to see hidden from the file picker
	- added unit tests
Merge pull request #165 from pedrofvteixeira/CDE_219

[CDE-219] Add the ability to hide arbitrary folders from the system file...