Allow a fixed list of change addresses.

Conflicts:

	src/wallet.cpp
Document the -change option.

Conflicts:

	src/init.cpp
Reworked fixed change address handling to parse addresses on init and store in a vector
within the wallet code.
Reverted accidental change to indentation.
Added Dogecoin copyright notice to wallet.cpp and wallet.h as modified files.
Removed comment about coin control from wallet.cpp as out of date.
Merge pull request #420 from rnicoll/1.7-dev-change

Add support for sending change to a list of address(es)