Fix parsing of geo coordinates in locale encoding (+ extend unit test)
Summary:
QString::toDouble in Qt5 no longer first tries the system locale
In tests also prefer QLocale::toString over "%L1", in some Qt versionns
(e.g. 5.6) the L might only work when QLocale::setDefault has been
explicitely called.
Test Plan:
Unit tests haven been improved and are all passing.
marble --latlon "46,09898 7,78307" in German locale works now as expected
Reviewers: rahn, nienhueser, Marble
Reviewed By: nienhueser, Marble
Differential Revision: https://phabricator.kde.org/D1994