Currently the values specified to --mongo, --mongod, or --mongos are only used by resmoke.py for the processes it spawns. This means that calls to startParallelShell(), MongoRunner.runMongod(), and MongoRunner.runMongos() use the executable in the current working directory.

We should add properties to the global MongoRunner object so that resmoke.py can propagate the path to the executable that the user specified at the command line.

Original description

Currently specifying the --mongod and --mongos options for resmoke does not result in those executables being used in MongoRunner, ReplSetTest, ShardingTest, etc.

Would be nice to pass those paths in TestData and use them in the shell helpers, so that the right executables are executed. This makes A/B testing during development much easier and less error-prone.