SHARE_PERIOD and CHAIN_LENGTH changes on DGC WDC CRC CSC ANC GLC

SHARE_PERIOD to 10 second target
-Additional shares for a higher chance of obtaining a share
-Lower p2pool share diff

CHAIN_LENGTH/REAL_CHAIN_LENGTH to 24
-Longer length of time to allow for finding of a share and for those
shares to be valid
-Amount of time to full payout increases but so does the time you
continue to receive payment after you stop mining.

Please delete your data folder (p2pool/data/) before using the new
specs.
These changes were carefully considered to allow a fair distribution of
shares to miners of various hash rates. Due to the current chain length
it is difficult for some miners to find a share as the p2pool hash rate
increases.