[kde-base/kwrite] Added ebuild for frameworks based kwrite.
[kde-base/kate] Added ebuild for frameworks based kate.

Changes with 4.x ebuilds:
- Added "addons" use-flag to provide a way to disable kate plugins.
Enabled by default, because it was silently builds in 4.x ebuild.
- Removed python use and dependency (pykde5 is not available)
- Changed description.