C/C++ Project Properties, Configurations management.
All CDT-specific property pages have unified controls
to handle configurations.

- Configuration:
- Specifies the selected build configuration from the list provided.
Note that configuration selection, unlike CDT 3.x, affects only property pages contents.
Selected configuration would not be made Active configuration (used to build project).
- Manage configurations
- Adds, removes, renames configurations. Sets active configuration.

