Code Simplification / Readability Changes

Summary:
Small changes thru the codebase to improve readability.
One potential crash fixed, and an old file removed.

Test Plan: run ctest. same results as running with master.

Reviewers: sitter

Reviewed By: sitter

Subscribers: broulik, sitter, plasma-devel

Tags: Plasma

Differential Revision: https://phabricator.kde.org/D22233