GIT_SILENT: Use KF5_MIN_VERSION as KF5_VERSION will be overridden by first KF5 find_package version as Found by Andreas Sturmlechner

Summary:
For most authors this uses the standing pre-approval from
https://techbase.kde.org/Projects/KDE_Relicensing, explicit
approval is needed from KDAB (hereby granted) and Andras Mantia.

This is the second batch for mailcommon, there's now still a handful
of cases left that need more research.

Reviewers: amantia

Subscribers: kde-pim

Tags: #kde_pim

Differential Revision: https://phabricator.kde.org/D16969

Patch created by Yan Pashkovsky

BUG: 400859

Yandex remote box has name |INBOX and it was not detected as inbox

Differential Revision: https://phabricator.kde.org/D16799

Summary:
This is only the first batch for mailcommon, and entirely based on
approval from https://techbase.kde.org/Projects/KDE_Relicensing.

Reviewers: mlaurent

Subscribers: kde-pim

Tags: #kde_pim

Differential Revision: https://phabricator.kde.org/D16808

GIT_SILENT: Cleanup: remove ECMOptionalAddSubdirectory which is never used\n ECMMarkNonGuiExecutable which is includes in ECMAddTests module\n CMakePackageConfigHelpers which is included by ECMSetupVersion