Add + Reset doesn't work

[Laoujin]

When adding (ga), you need to do a new gs before you can do a reset (grs)

When adding, we could add them to the staging area in memory

Not sure if this is worth the hassle (a 'gs' is quickly done)
Because if you do:

gs
ga 0-2
--> grs 0-2 would now reset those two files

gs
ga 0-2
gs
ga 0-2
--> grs 0-2 would now reset the first added files
--> grs 3-5 would reset the last added files
--> That's probably just plain confusing

Would be possible to just do this if the staging area is empty at that point.

But then:

gs
ga 3-5
--> to reset should we now do a "grs 0-2" or "grs 3-5"...