Suppressed warnings
Refactor workspace and workspace factory

Added MED_WORKSPACE_INTERFACE macro in medAbstractWorkspace, which
automagically creates a series of static and instance methods to
standardize and simplify the regsitration of a workspace. Also, sorts
workspace by name in the menus.
Refactor data and data factory

Added MED_DATA_INTERFACE macro in medAbstractData, which
automagically creates a series of static and instance methods to
standardize and simplify the regsitration of a data type.
Refactor toolbox and toolbox factory

Added MED_TOOLBOX_INTERFACE macro in medtoolbox, which
automagically creates a series of static and instance methods to
standardize and simplify the registration of a toolbox.
Refactor settings widget and setting widget factory

Added MED_SETTINGS_INTERFACE macro in medtoolbox, which
automagically creates a series of static and instance methods to
standardize and simplify the registration of a setting widget.
Merge pull request #150 from fvichot/refactoring-factories

Refactoring factories
Some cleanups in the DICOM importer, and fix importing some sequences

Some DICOM sequences had each slice with an independent Series Instance
UID, thus confusing the importer which would import each slice as a
separate volume. Now we rely on Series Description, hopefully more
reliable. I also removed the Series Number from the volume signature.
Change computation of bounds for window/level (handle negative values)
Change composite param to use QHash to set values (was buggy before)
Remove useless qdebugs
Solves the problem of window level using the sliders with images having small value ranges
Window limited to 0 everywhere
Correct number of decimals shown based on current step
Correct WL transmission bug between 3d and 2d view
Added some comments to justify the use of (void), and cleaned-up some commented code
Merging fcollot:remove-warning, closes PR #148
Correct zooming bug in 3d mode
Levels are not constrained by image values anymore
Merge pull request #157 from ocommowi/wl-composite-bug-correction

WL composite bug correction
Correct some stuff in ROI loading, still buggy