Add integer argument generators

[lchladek]

It would be nice to replace this:

[parameter.seed]
values = ["1", "2", "3", "4", "5", "6", "7", "8", "9"]

with this:

[parameter.seed.sequence]
start = 1
end = 9

or this:

[parameter.seed.random]
lower = 1
upper = 1000000
count = 10

Specifically, this is to add sequences and random generation, both of which are useful for experiments/grid search.
Sequences would use start, end, and step? (default = 1) while random would use lower, upper (default are positive integer limits) and count.