Fix build break in examples/priv.cpp resulting from library changes to elliptic_curve_key.
Support for setting compressed flag on new_keypair and set_secret (set by default).
examples/priv: Use new elliptic_curve_key.

The way ECK is used has changed a bit, so accomodate the example.

Announcement: http://lists.dyne.org/lurker/message/20140116.144459.92a367f2.en.html

Issue: https://github.com/spesmilo/libbitcoin/issues/33
Merge pull request #34 from veox/issue33

examples/priv: Use new elliptic_curve_key (fix issue #33)
rename hosts filename to hosts.p2p (more descriptive)
protocol start doesn't stop if handshake ip resolution fails.
remove obsolete detwallet test
ported detwallet mnemonic stuff to libwallet
stealth functions.
add mmap file utility class.
stealth database part of blockchain, and able to query values.
add state to nodes in getx_responder so we can track hash_continue value for remote node downloading blocks.
fix typo and warning
correct error message.
link with info with stealth_database
index stealth transactions in the database (write).
patch by William Swanson fixing my erroneous C++: see ML thread called [Libbitcoin] [PATCH] Fix C++11 language violations. Archive link: http://lists.dyne.org/lurker/message/20140214.055052.2d0bc4dd.en.html
update checkpoints.
implement script op_counter (nOpCount from EvalScript())
implement bitcoind checkmultisig bug