`gegen group` misc issues about stata-gtools

[mcaceresb]

I note in the README that gegen does not respect group order; perhaps I should change the function name since you find it misleading? (I'll fix the wrong option bug)

[sergiocorreia]

Another problem is that the new IDs seem to have holes:

sysuse auto, clear
gegen id = group(turn) in 20/30
tab id

(groups 1-4, 6, 8, etc. are missing)

[mcaceresb]

I see. This is not a but per se, though, since all the groups are there and the ID is unique, but I agree that coupled with the order issue it makes the ID rather confusing.

[mcaceresb]

The IDs should no longer have have holes, and extraneous options now give an error. See 0.6.10 (master branch). However, the order of the IDs is pending a future release. I am opening a new issue for that. (See issue #6).