fixing the ValExpression to be usable only from within conversions
refactored conversion rule specification
fixed units tests
fixed units tests
fixed migration scripts
fixed an issue with val exp's unit
fixing the tutorial
phys units devkit setup
minor enhancements for the units editor
added missing dep
Merge remote-tracking branch 'origin/master'

Conflicts:
	code/languages/com.mbeddr.ext/tests/test.ts.ext.units/models/test/ts/ext/units/main@tests.mps
Merge branch 'master' of https://github.com/mbeddr/mbeddr.core

Conflicts:
	code/languages/com.mbeddr.ext/tests/test.ts.ext.units/models/test/ts/ext/units/main@tests.mps
removing legacy documentation about installing yices and nusmv
fixing the const in typedef original
improvement of the random models generator
small fixes in models-generator
improving type-system rules for stacks and ring-buffers
further improvement for stack and ring-buffer
removed mistakenly duplicated constraint descriptor
introduced conversion specifier with any type