Port away from KDELibs4Support

- macro_bool_to_01 comes from KDELibs4Support, the CMake vars it was setting
  aren't used
- QKeySequence operator int() has been obsoleted for ages; looking at the Qt
  code it returned QKeySequence[0], which is simple to do that manually
- use KGlobalSettings enum values directly, IIUC the plan is to use
  KConfigWatcher for all the KGlobalSettings stuff
- kimagecache.h is actually in KGuiAddons not KDELibs4Support, so we can use
  that (and have to link against KCoreAddons for KSharedDataCache...)

Remains kcms/dateandtime for ktimezone* classes used for the timezones
widget; d_ed said the plan is to port it to QML.