Doubles: Unban Sky Drop

Sky Drop is no longer glitched in BW2 and thus available, so Doubles is unbanning it.
Fix Perish Song bug in Doubles

In Doubles, there's the possibility that battle.sides[i].active[j] 
does not exist, thus causing a crash. Add a check for that.
A non-existing Pokémon is not counted for result.
If there's no active Pokémon, there's no field Perish Song 
effect whatsoever.
GP 1/2
Unban Darkrai in STABmons
Update smogdex command: add option to link to doubles formats analyses

Add a third optional parameter to link to a vgc2012, vgc2013, 
or doubles analysis. It only works for gen 5 onwards. If you 
intentionally don't set generation, it will default to 
latest generation and check the parameter for doubles.
Fix styling in last commit
Crash hotpatch gracefully and inform of the exact error
If a hotpatch fails, it now fails gracefully and informs of the
error stack trace.
Move Doubles from othermetas command to tiers command

Since Doubles is going to be official from gen 6 on and it's 
on adaptation period, show it on tiers now so users get 
used to it.
Make redir not redir to the same room
It's redundant.
Gen 1: Implement partial trapping 0 pp bug
When a partial trapping move is executing its 0 pp sequence, if
the opponent switches the pps get rolled back to max.
Support using room title for /redir
Fix Flash Fire accuracy check with Fire-type moves
No Fire-type move should fail against Flash Fire Pokémon.

Test on two turns:
Flash fire is making Will-O-Wisp accuracy to true.
Flash fire is making Will-O-Wisp accuracy to true.
Accuracy for Earth Power: 100
Accuracy for Earth Power: 100
Accuracy for Will-O-Wisp: 75
Accuracy for Will-O-Wisp: 75
Accuracy for Substitute: true
Accuracy for Substitute: true
Fix Storm Drain accuracy check for Water-type moves
Water-type moves should not fail against Storm Draim Pokémon.

Test, Gastrodon + Qwilfish, turn 2 switching the first to Escavalier:
Storm drain is making Hydro Pump accuracy true
Storm drain is making Hydro Pump accuracy true
Storm drain is making Hydro Pump accuracy true
Storm drain is making Hydro Pump accuracy true
Accuracy for Recover: true
Accuracy for Recover: true
Accuracy for Hydro Pump: 80
Accuracy for Hydro Pump: 80
Gen 2: Add base files
Formats for its own validateSet, statuses, learnsets (from Veekun),
items, move changes, formats data for tiering, ability none,
and battle scripts.
Gen 2: Implement Hidden Power
Typechart is necessary for the types IVs for specific hidden powers.
Gen 2: Add format and ladder
Merge pull request #290 from Slayer95/patch-1

Support using room title for /redir
Gen 2: Set format to debug mode

Set the format to debug mode for easier test when a user reports a problem.
Gen 2: Correct Hidden Power Base Power calculation
Brackets were missing.
Gen 2: Fix bug on critical hit with debuff
If you have an attack debuff and get critical hit, turn crashes.