Export refactor

Cleanup of writer's handled()/registered()/create() methods
added file format selector combobox in dialog on export
Adds the right suffix when selecting an exporter

Also, fixed a memory leak, and removed the filter list with a hack
Added supportedExtensions() methods for writers missing one
Change back a patch that broke the priority list, and display the exporters' list according to priority order
Fix merge pb after rebase, remove 2D exporters
Some cleanup in itkDataWriterPlugin
Correct warnings in medcompositeDataSets
Add ITKReview in target links of examples if compiling with it
Removed the Philips REC writer, which doesn't work with 3D images
Remove the COPYING and help files from the pluginGenerator
Remove dtk_build_doc from cmake tempplates.
remove the 'Generated by medPluginGenerator' statement from CMakeLists.
new types supported for plugin generator: workspace, reader and writer
Update registration plugin template to match ITK4 RPI
Update registration plugin template to match ITK4 RPI
correct typo, add missing arg to workspace source file generator
complete test
remove useless args
add function to generate IO header and sources
Merge pull request #115 from ocommowi/fix-all-compilation

Fix all compilation