enhance group/sort command in ReplicateErrorWA

[Johan Enell]

Instead of just grouping on one vairable in the assayname the user should be able to specify a number of vaiable to sort by.

B1_T1_D1_4636
B1_T1_D2_4176

B1_T2_D1_3676
B1_T2_D2_5676

B2_T1_D1_4636
B2_T1_D2_4176

B2_T2_D1_3676
B2_T2_D2_5676

assayname %_%_%_%
group 1,2
sort 3

First group on vaiable 1 (B1, B2) then sort on varable 2 (T1, T2) which will result in the 4 groups above. Each group is sorted on the value in varible 3.

Parameter group will accept a comma separated list of numbers.
Parameter sort will specify what group to sort on. If not defined no sorting will be done.