Doc additions to clarify the behaviour of get_value() in cases where the variable is not passed to the solver.
Doc additions to clarify the behaviour of get_value() in cases where the variable is not passed to the solver.

JElchison/Numberjack,eomahony/Numberjack,eomahony/Numberjack,eomahony/Numberjack,JElchison/Numberjack,JElchison/Numberjack,JElchison/Numberjack,JElchison/Numberjack,eomahony/Numberjack,eomahony/Numberjack