Restore normal development cycle

1. Archive NEWS for 0.7.0 release
2. Add new blank NEWS file
3. Bump version to 0.8.0 and restore "-dev" suffix

Change-Id: I21febc042faeed294f3beeb5e683535dbf011e8f
Signed-off-by: Freddie Chopin <freddie.chopin@gmail.com>