Omedit changes modifiers in string when the parameters pop-up window is used

[Andrea Bartolini]

To reproduce the bug:

1) create a new model

2) put into the model an MSL source block, e.g. a RealExpression,

3) write the expression using the parameters pop-up window, e.g. time + 1

now the model appears as below:

model test
  Modelica.Blocks.Sources.RealExpression realExpression1(y = time + 1)  annotation( ...);
end test;

4) change the expression from the parameters pop-up window, e.g. time + 2, Omedit change it in a string !!!

model test
  Modelica.Blocks.Sources.RealExpression realExpression1(y = "time + 2")  annotation( ...);
end test;

OMEdit 1.12.0~dev-104-g72c7018
Connected to OpenModelica 1.12.0~dev-222-g56170d9

sysop linux Ubuntu 14.04