Refactor KoPageFormat
* move enums to exist inside the namespace instead of being global
* Rename enum values to be CamelCase
* Split KoPageFormat and KoPageLayout in individual files

Stop compiling the page-layout widgets since they are too complex for most apps, and since 2.0 not complex enough for kword. So the plan is to make new ones in kword and see if there is something available for reuse afterwards.
The kword page-dialog is a still work-in-progress, doesn't work yet.