Summary:
The GUIenabled variable is just used if not in KDEVELOP_SINGLE_APP
mode, but silencing the warning with unguarded-ifs unclutters the
code a bit and has no sideeffects.

Use brace-initialization for QStringList

No need to test for isEmpty before using Q_FOREACH

If the container is empty, it will just do anything
on the foreach macro. this also reduces the indentation
level a bit.

Rename variable p to project

The outer loop has a variable named p, and while C++ accepts
that inner variables have biggest priority than outer
variables, this could be a potential human mistake.

Replace 8 ocorrencies of const char* to QString to a single QString

QString is UTF_16 internally, so creating just one QString
for a given string is better than runtime-creating a few more
via const char*.

Test Plan: compiled and tested

Reviewers: kfunk, apol

Subscribers: kdevelop-devel

Differential Revision: https://phabricator.kde.org/D4101