Implement DBHandler::queryMultiple.

Add function to DBHandler to query for multiple records and have them
passed to a callback in order.
Cleanup, bug fixes.

Signed-off-by: FellowTraveler <F3llowTraveler@gmail.com>
Merge pull request #30 from FellowTraveler/gui

Cleanup, bug fixes.
Bug fixes, cleanup.

Signed-off-by: FellowTraveler <F3llowTraveler@gmail.com>
Merge pull request #31 from FellowTraveler/gui

Bug fixes, cleanup.
One more bug fix.
Merge pull request #32 from randy-waterhouse/master

One more bug fix.
Add NMC_NameManager with registration.

Add nmc_names table to internal DB, and use it to persist name
registration processes.  They can be started now, but are not yet
automatically finished.
Merge branch 'master' of https://github.com/Open-Transactions/Moneychanger
Merge branch 'master' into namecoin-credentials

Conflicts:
	src/moneychanger.cpp
	src/moneychanger.h
	src/moneychanger.pro