Support new bulk import API in shell

[keith-turner]

This is follow up work for #436. Need to support the new bulk import API in the shell.

[milleruntime]

@keith-turner do you think the shell should support the old and new bulk import APIs?

[ctubbsii]

The shell has its own API. I don't think we need to confuse it with multiple commands that map to different Java APIs. We can just change its options, for example, to make failure directory optional.

[milleruntime]

So you are saying have the one command support both? If you pass a failure directory use the old technique, otherwise use the new one?

[ctubbsii]

One command, but should use the new implementation if the failure directory isn't specified.

[ctubbsii]

Perhaps... but I think it might be better to only use the new one, leaving the failure directory arg as optional, so it doesn't break people who provide one, and give a deprecation warning if they do provide one.

[milleruntime]

Think we need to worry about backwards compatibility? The way the CLI options work, I think I am going to have to change the command from:
importdirectory <directory> <failureDirectory> true|false
to
importdirectory <directory> true|false [-f <directory>]

[milleruntime]

I found the NO_FIXED_ARG_LENGTH_CHECK so I will make the command work with old and new based on number of parameters.