Using loop index as part of an equation

[Argimiro Resende Secchi]

The use of an index variable as part of an equation, such as the following modification in the sample_arrays.mso file:

Error: Failed to load processor mso

No macro or processor named 'mso' found

is not allowed in the current version. The index variable should be treated as an integer parameter.

[Rafael de Pelegrini Soares]

Enhancement implemented on the development version (0.9.52). Actually it was already implemented, the only problem was related with the UOM checking in such equations.