New launch UI
Support for validation and error reporting.
New implementation of "Add Executable".
Fix NPE when creating new launch.

Change-Id: Iaa1bff410621559c8471d1b4ed8b2eda2c9e1b6b
Implemented event handling, enablement/disablement for the model
elements as well as support for core sessions.
Added "Debugger Settings" and "Connection" elements.
Added more model and UI elements.
Added connection related elements. Store and restore the current state.
Bug fixes.
Added the "Working Directory", "Environment", "Build settings" and
"Debug Options" elements to the model and the UI. Bug fixes.
Implementing the model based launch delegate.
Implemented "attach to process".
Added support for postmortem debugging.
Removed all dependencies to ILaunchConfiguration from the model
elements. Added support for working directory settings
Moved up the basic debugger settings.
Modified and refactored the "Breadcrumbs" class.
Breadcrumbs.getCurrent() should return the component object not
ComponentData.
Replaced Combos with PillsControls.
Various UI improvements.
Implementation of "Build Settings".
Implementation of the new "New Executable" dialog based on the new
model. UI improvements and bug fixes.