Revert "SERVER-6071 use command on local.slaves instead of cursor"

This reverts commit 2267744af0e972bceccb4ff4e9ed19a1ed639d2e.

Revert "SERVER-6071 correct assert code"

This reverts commit 85ca38c33e4aaebad539e78a05aed329b09c1208.

Conflicts:
	src/mongo/db/repl/sync_source_feedback.cpp

Revert "SERVER-6071 use command on local.slaves instead of cursor"

This reverts commit 83ecb9775b7997dd5115c53f6ea30d2e368a4244.

Conflicts:
	src/mongo/db/repl/replset_commands.cpp
	src/mongo/db/repl/sync_source_feedback.cpp
SERVER-10103 add debugging output