This basically reverts 839332d2

Also: Make all the "Restart dialog" look similar:
- Title now is in Title Case not Sentence style
- Title always is "xy Changed" not "xy Change"
- Text always is "Restart for ... to take full effect?"
- Buttons always are "Restart" and "Dont' restart"

Change-Id: Icac1b848ef48678753f392f954623ef21eb8f6ff
Reviewed-on: https://git.eclipse.org/r/c/platform/eclipse.platform.ui/+/188195
Tested-by: Platform Bot <platform-bot@eclipse.org>
Tested-by: Lars Vogel <Lars.Vogel@vogella.com>
Reviewed-by: Lars Vogel <Lars.Vogel@vogella.com>
Reviewed-by: Sebastian Ratz <sebastian.ratz@sap.com>
Reviewed-by: Matthias Becker <ma.becker@sap.com>