Changing the provided Code may lead to unwanted behavior

[LeonMatthes]

If you replace the Code that is provided by the MorphicTutorial and then evaluate the code, some strange behavior happens:

• if you remove a provided variables declaration it is still defined at runtime, which is kind of weird, because it is no longer visible by the user
• If you add new variables to an already provided variable declaration, these variable declarations will result in some very weird behavior, in which the code compiles and runs fine, but when you open the method it was compiled into, the variable declaration is missing, causing you to be unable to save the method again, because it contains an undeclared variable
• if you change the method declaration in an exercise like "Swapping colors", it will compile the new method name into the ColorfulMorph, which is most of the time not what you want, especially as there is no warning or confirmation, it just silently compiles it, possibly leading to problems when rerunning the exercise later.

Possible fixes:

1. Provide a warning if such user change is detected (possibly difficult to find every change, error prone)
2. Lock down the text to not allow change by the user (may require an extra text field)

[LeonMatthes]

Currently working on option 2.
Adding a second text field which is locked seems to be the best option at the moment.
This does however mess with the syntax highlighting., as the parameters of the Method/Workspace are no longer declared inside the text field. I am currently working on fixing this by creating a custom Environment for the TextStyler so that it at least recognizes the parameters as globals and not as errors.
This is not working yet, I am not sure why, therefore any help to why the changes made in commit cd3bbb6 don't work would be appreciated.

[LeonMatthes]

Maybe adding a specialisation of the Parser will help with this, as the Environment solution does not seem to work.
Will be working on this angle for the next days