- that means moving the widget and all its signal/slot connections
- Create new interface `WorldImageCorrespondence` for all calculations between image/pixel coords and world coords (dispatches to `ExtrCalibration` when 3D, else uses old 2D coord sys)
- Moves the methods for wold image correspondence from the `ImageItem` to the newly created `CoordinateSystemBox`
- During this change: Make the 2D coord system not depend on `mapToItem`; its now using normal affine transformations (`QTransform`) instead, which incidentally should make #383 easier
- `imageSizeChanged` is now a slot of `Control`, such that `ImageItem` can call it without having a reference to `Control` by sending a signal (Following that: image item is now now directly depending on control anymore)
- Some include clean-up

Remove the inheritance from `TrackPerson` in favor of composition, this allows a better handling of interactions with the `TrackPerson` as changes now go through defined interfaces.

Main changes:

* `TrackPerson` no longer **is** a `QList<TrackPoints>`
* `TrackPerson` now **has** a `QList<TrackPoints`
* new function `deleteFrameRange` which will delete a range of frames, but leaving no gaps in the middle
* `lastFrame` is now compute and not stored, hence no need to update it
* `firstFrame` is set when creating a `TrackPerson` and will be updated when needed automatically

The image center (or principal point) could be set wrongly if the previous project had a significantly lower resolution, disallowing values for cx,cy such as the correct ones for the next project.

-> load video (and therefore imagesize) first

New procedure for dealing with invalid pet-file:
- save current state before loading new file
- open new file
- throw exception on erroneous value
- catch exception at top level and restore old state
- show error message

- Introduces `ExtrinsicParameters`-Struct
- Extract `ExtrinsicBox` from `Control`

- Move slots to FilterBeforeBox when concerning its elemets
- Fix Tab order of new extracted widgets
- Delete dependency to Control by AutoCalib

- Move "filter before" GroupBox into own widget
- Move "intrinsic" GroupBox into own widget
- Save intrinsic calibration in struct
- Use said struct as parameter for `CalibFilter`
- Add `setValue`-helper function for loading values into UI respecting min/max
- Move PeTrack-Version from Setter to Constructor of Petrack-object
- Add Unit-Tests

- updateControlWidget should set new maximum person Nr
- in 3a2030ba wrongfully changed to set current person; revert this change here
- reintroduce updateControlWidget to editTrackPersonComment

- Changes shortcut for jumping to frame

This
 - enables editing the .ui-file without changing control.h; reducing recompile time
 - encapsulates the widgets themselves from everything outside of Control

- Remove Ctrl+E Shortcut for video view export
- Make Shortcut Shift+T usable no matter which tab is selected

- Preparation on a switch to MSVC on windows
  - Reason: Support for vcpkg, while MinGW is only community supported

- Alt + holding left mouse-button enables to move the point under the cursor by dragging it with the mouse
- Point isn't moved anymore as soon as either the mouse button or alt are not pressed anymore
- Added documentation in "Key Bindings" Window for this and for !188 (Jumping to frame of trackpoint under cursor; Alt + dbl-Click)

Add AutoSave mechanism. The manual changes to the trajectories are counted. After 10 changes, the trajectories are exported to a hidden file. This hidden file can be loaded in the case of an crash of PeTrack. The project file is saved time based.

Enables to move to a frame by clicking on a trajectory via Alt + Dbl-LClick