Pool set up and valid roles

## Valid pool roles are:

mine = mines on this pool as usual (diff.*0.43)
mine_c = mines score pools based on this simple formula
         (n/shares per unit time)/c ∝ (n/hashrate)/c = n/(hashrate*c)
mine_slush = mine_c with c: 300
mine_lp = monitor and makes educated guess mining
  without using the api
mine_lp_force = mine untill lp is triggered and then resets
  back to previous role (don't use as default role for pool set-up)
mine_nmc = setup pool for NMC mining
mine_ixc = ixcoins pool and diff.
mine_i0c = i0coins pool and diff.
mine_scc = solidcoin pool and diff.
mine_force = ignores active scheduler and mines only this pool
  (don't use as default role for pool set-up)
backup = point bH this pool has a good payout system that can use to
  maintain achieved efficiency (see bh.cfg for more backup options)
mine_charity = usually mines the pool when they hit
  and increased diff block (bad luck) + normal mining
info = shows share count for this pool on stat page
disable = disables pool completely (you can delete 
  pool's entry in this cfg file too)

## Pool set-up:

role:          tell bH what kind of mining is wanted at
               this pool, pick a valid one from the list above
penalty:       floating point number, # of shares will be
               multiplied by this number when calculating
               shares against difficulty
               BACKUP SERVERS: Set it to the percent the server takes. 
               The penalty/100 is added to the reject rate when calculating 
               which server to use
lp_penalty:    normalize LP's of this pool with "x" seconds (greater for fast
               LP response pools)
percent:       keep submitting shares to pool, % value from you total output
               (1% = 1 share every 100)
c:             this variable is used together with "mine_c" role and
               determines how long it takes shares to decay in value on
               score pools (more info on page 200, bH thread in main forum)
priority:      use this setting for every pool if you want bH mine by your
               personal preference of them (0 = highest prio, 1 = lower, etc.)
refresh_limit: pool's api refreshing interval in seconds
user_agent:    HTTP User-Agent header to set when retrieving pool stats
               Overrides the default in bh.cfg
user:          worker username you setup for this pool, u can use {}
               to have bH mine different worker accounts ex. user_{bHworker}
pass:          password you have for the worker (not needed for all pools),
               use {} for password too, ex. password_{bHworkerpass}
wallet:        only for Payouts plugin, use a different address for each pool