new way check for build ways

[Andarix]

I am revising the exam for way build.

The previous functions ( get_fullway()/all_control() ) were too rigid regarding directions.

The new version checks more flexibly. However, the last field is not always selected. This occurs when the distance to the target field does not decrease.

Currently, road construction in Chapter 2 Step G and railway construction in Chapter 3 Step B have been changed.

code found here