The icon 'table' does look different for some reason. Taking the second 
best available icon.

MeasurePipe is now standalone.

Remove button is permanently visible and bith buttons are now in the 
lower left corner

This feature is incomplete. Button is hidden until it's done.

Row first.

#643

Frames are meant to be in the background and putting elements on top is 
common with them.

Used by reference and delete dialogs.

This is only used by the Editor. It was in common while the 
SanitizationService was used by the Player which then could display 
errors. Sanitization has been refactored and this is no longer needed.

Separating code changes is rather hard right now, so there is a lot of stuff that is part of this commit that should not. Details below.

- All elements have static fields that holds their title and icon. This way dynamic lists can be built (for example for delete dialog) which show title and icon for all elements. ALso icons and names can be changed in one place.
- Template-Tab has been added. This should have templates to help creating groups of ui elements. This is work in progress and there are actually no templates yet. So this will change or even be removed in the future. This is mostly UI, the code is "TODO".
- Refactoring and improvement for delete and reference dialogs
- Delete logic refactored for elements, sections and pages. There are no longer different dialogs when references are found, but instead one dialog that can do both.

Visual overhaul and another way of inserting a section. The section code 
is saved to a global variable which can be used as well. Does obviously 
not work accress edit sessions or different units, therefore the old way 
is preserved.

This sets them up from the central UnitView.

Only works for a few commands (mainly page and section stuff).

- Adds new menu to page-bar, which shows issued change commands with a 
button to rollback the latest change.
- Added warning to the UI element that this is a experimental feature 
and can destroy units.
- Undo is done by having the normal function to apply the change to the 
unit-object and another to undo this change. The HistoryService manages 
the list and calling rollack (via UnitService).
- Further refactiring to the unit services.