Change log TCRP

Version 1.1 (2022-12)
Major adjustment
- the TCRP model is updated to run smoothly on PCRASTER 4.4.0

1. all ldd() commands do not produce the right data type. 
The command 'spatial()' is added which solves the problem.

2. The directional data in the tilldir.map causes problems. 
The -1 data is changed to 'mv' when the data type is changed to scalar.
Also the boolean command to find the tillage and 'no tillage' areas does not work correctly:
	Till = boolean(if(TillDir1 ne directional(-1), 1, 0)) -> gives TRUE everywhere...
	If the input map however is scalar this function works well.
	When calculating with directional data - the result changes all -1 into mv. 
	This results in a final output only including tilled fields, 
	but we also need results for no tillage fields!
	
	The main problem seems a redefinition of the directional data type. 
	During a conversion '-1' is not regognized as 'no direction' but changed to 359 degrees.
	This means that we can only convert files with direction data in cells, 
	all other cells should have 'mv'. When needed attributes can be combined using cover().
	This principle is worked throughout version 1.1
	
Adjustments result in correct output. Main method is to use the cover() function a lot. 
The input map 'TillDir' is no longer directional but scalar!


Minor adjustments:

1. the mapedge was calculated as 1.5 * dx on the edge of the fields, this does not cover all 
	the pits at the borders. by increasing to 4 * dx this improves.
	the mapedge stays a bit difficult and some pits remain at the border... 

2. pits.map is saved and updated by the different models to check for pits in the ldd

3. the lddtill.map contains some 'mv' within the fields domain. Just before saving the lddtill.map these are filled with lddtopo values.

After this all code seems to work fine.