(N.B. This change also includes the "freezing" phase when assigned a Freezer.)
I'm sure that Climbers performing the "oh no" phase is only present due to it being standard behaviour in earlier Lemmings ports/clones, but I'm increasingly thinking that it's not really necessary and doesn't actually make much sense in the context of other skill actions.
Reasoning: in order to perform this state, the lemming has let go of the wall and should therefore fall. When falling, lems explode immediately. Also, other movement-based states such as Swimming, Floating, Gliding, Ballooning, etc have the lem expode immediately; it seems to me that Climbing and Sliding should follow suit.
I've gone ahead and implemented this already (Commit 845c13561 and 8641bde91), but I'll reverse the change if people feel strongly that the state should be kept as it is.
