Code cleaning and harmonization.

Harmonized types of IOException thrown accross all Exchange classes.
Now retrieving all strings from JSON with asText().
Replaced explicit iterators with while cycles for implicit iterators
with for cycles.

Fixed Maven groupId.

Doubled connection timeout due to the lag of Chinese exchanges.

1Bse Added.

OkCoin updated to handle futures.

Added exchanges: Atomic Trade, C-CEX, CoinMkt, Coins-E and Vircurex.

Removed inexistent pair from ANX. ExchangeTest now tests all retrieved

pairs.

Added Bitfinex to exchanges list.

Added Peatio, CHBTC and 796 Exchange.

Added testFailGetLastValue to some exchanges.
Renamed exchanges which were missing "Exchange" as class name suffix.
Moved construction of pair's list into a static block.
Rearranged packages for easier code access.