Added the possibility to use two regaular expressions in  @dynSeries/extract method.

*Example*

Suppose that a dynSeries object contains the following set of variables

GDP_1
GDP_2
GDP_3
GDP_4
GDP_5
GDP_6
GDP_7
HICP_1
HICP_2
HICP_3
HICP_4
HICP_5
HICP_6
HICP_7
Consumption_1
Consumption_2
Consumption_3
Consumption_4
Consumption_5
Consumption_6
Consumption_7

Then the syntax:

b = a{'@GDP,HICP@_@1,2,3@'}

will instantiate a new dynSeries object containing variables:

GDP_1
GDP_2
GDP_3
HICP_1
HICP_2
HICP_3
Added unitary test in dynSeries/extract method.
Added the possibility to use two regular expressions in dynSeries/subsasgn method.

As in dynSeries/extract we consider a tensor product.
Added unitary test in dynSeries/subsasgn.