Draft: Resolve "Short circuiting and lazy evaluation"

Closes #49

examples/short_circuiting.vm

+"""
+variables "a" and "c" will not be evaluated
+tests with: texts script -f short_circuiting.vm [-m deferred] --enable-logging --logging-level DEBUG
+"""
+
+a = 'abc'
+b = if(true, 'xyz', a)
+print(b)
+c = a == 'abc'
+d = false and c
+print(d)
+
+e = false
+print(all(e, c))
+print(any(not e, c))