Added the possibility to pass a range of dates to the dseries constructor.
New syntax for populating an empty dseries object.

If ts is an empty dseries object with a defined range of dates:

ts = dseries(dates('1990Q1'):dates('1990Q4'));

Then the following syntaxes are valid:

1. ts(:) = 1;
2. ts(:) = [1, 2];
3. ts(:) = randn(4,1);
4. ts(:) = dseries(1);
5. ts(:) = dseries([1, 2]);
6. ts(:) = dseries(randn(4,2));
7. ts(:) = dseries(randn(4,2),dates('1950M1'):dates('1950M4'));

Remarks.

[1] In cases 1., 2., 4. and 5. the single observation is replicated to match the number of dates in ts.

[2] In cases 4. to 7. the dates in the right member of the assignment are lost (ie ts.dates is not affected by the dates defined in the right members).
Changed @dseries/display method. Do not display all the variables if the number of variables is greater than 10.

Note that the behaviour of @dseries/disp is not changed (displays all the variables).