Summary:
- As we don't have C++17's [[fallthrough]], rely on GCC'd detection
of fallthrough comments.
See https://developers.redhat.com/blog/2017/03/10/wimplicit-fallthrough-in-gcc-7/
- Add some missing copy assignment operators as reported by
-Wdeprecated-copy
- Cast a Eina_Bool/bool narrowing conversion
Reviewers: zmike, brunobelo, felipealmeida
Reviewed By: zmike
Subscribers: cedric, #reviewers, #committers
Tags: #efl
Differential Revision: https://phab.enlightenment.org/D9934