Code Mining: code mining background should not remain unchanged when selected

[humphreygao]

[mickaelistria]

I've a patch that implements it at https://github.com/mickaelistria/eclipse.platform.swt/pull/new/selection-bg-codemining .
However, the selection background in Eclipse IDE which is inherited for the OS (Fedora in my case) is a darker blue and makes reading codemining impossible. So if we want to adopt it, then we need also to adapt the code that draws the code minings so it changes color when selecting the right parts of the line. It all becomes trickier and this is not critical enough to me; so I'm giving up on this topic for the moment to focus on more important bits. Maybe later, probably never ;) But if anyone else wants to work on it, they're more than welcome to take the patch above as a starting point.