Enable use of MLM variables in curly braces

[hflicka]

As of the Arden Syntax standard, MLM variables may be used in curly brackets in an implementation-specific manner, then being substituted by their values.
I propose using a bash-style syntax such as $varname or $(varname) (can't use curly braces here).

[hflicka]

I recently enabled the reading of MLM variables from the Java 'outside'. That is, the MedicalLogicModule interface has received a new function getValue(String name) which returns the value of a MLM Variable. Using this function, it is possible to read MLM variables in the Execution Context, given that the MLM is known to the context.

[Tetr4]

This issue was moved to PLRI#11