Move MapReduce option parsing somewhere it can be accessed by mongos and mongod SERVER-7122

Conflicts:
	src/mongo/SConscript
	src/mongo/db/commands/mr.cpp
Add required privileges to MapReduce command SERVER-7122
Remove example code from server_parameters.cpp
Store cursor namespaces in mongos. Necessary so mongos can check authorization on the cursor's ns in killcursors. SERVER-7572

Conflicts:
	src/mongo/s/cursors.h
Make AuthorizationManager check if an admin user exists on every localhost query rather than just at initialization time.  SERVER-7572 SERVER-7126
Set up an AuthorizationManager for every ClientBasic, not just those for incoming client connections SERVER-7572
Add method to AuthorizationManager to check authorization for an ActionSet SERVER-7126
Authorize internal threads to new AuthorizationManager. SERVER-7572

Conflicts:
	src/mongo/db/repl/rs.cpp
a simple unit test for seeded random
make a SecureRandom class
PseudoRandom isn't seedable on windows
getnonce uses SecureRandom

Conflicts:
	src/mongo/db/security_commands.cpp
SERVER-7626 Provide a facility for disabling the mongo challenge-response commands in server source.

This patch provides a mechanism for disabling the "nonce" and "authenticate" commands at runtime.  A
separate patch, in the subscription codebase, provides a startup parameter for choosing authentication
mechanisms to support.

Related to SERVER-7119.

Conflicts:
	src/mongo/db/security_common.h
For SASL authentication in the client, send the saslStart/Continue commands to the right database.

For users whose credentials are stored externally, send the command to
"sasl", for all other users, send it to the database whose system.users
collection contains a document for the given user with a "pwd" field.

SERVER-7795
Update comments to refer to $sasl instead of $external. SERVER-7795
SERVER-7122 Setup ActionSet for internal-only actions
SERVER-7122 Make cloning commands not work with auth is enabled

Conflicts:
	src/mongo/db/cloner.cpp
SERVER-7122 Add setParameter option to enable/disable testing commands

Conflicts:
	src/mongo/db/commands/hashcmd.cpp
	src/mongo/db/dbcommands.cpp
	src/mongo/db/dbcommands_admin.cpp
Support logging out of a database in AuthorizationManager SERVER-7572
SERVER-7778 Introduce a --setParameter option to the mongod and mongos command lines.

Usage:  --setParameter name=value or --setParameter=name=value.

Conflicts:
	src/mongo/db/cmdline.cpp