Recursively expand directories before delete and enable folder rename functional tests

[wilbaker]

Fixes #202

Summary of changes:

• Added a new kernel->user message MessageType_KtoU_RecursivelyEnumerateDirectory
• The new message is sent from the kext to user mode whenever a directory delete is about to occur
• Handling of the message is done by the user mode library. The lib walks the directory and asks the provider to expands any empty directories it finds
• Enabled partial folder rename functional tests

[sanoursa]

The code looks good but it does potentially introduce more complicated error modes that I'd like to understand better.

[wilbaker]

@sanoursa @nickgra this is ready for another look, let me know what you think.

[nickgra]

Left some nits, but LGTM.

[nickgra]

This TrySendRequestAndWaitForResponse and the one below structure their ternary statements differently. I have a preference for how I think it should look, but you can ignore that so long as they're consistent with each other :)

Can we pull the comparison up into a separate variable here too? Additionally, this line is getting long, I'd rather we break it up into 3 separate lines like we do in the below addition.

[wilbaker]

This TrySendRequestAndWaitForResponse and the one below structure their ternary statements differently. I have a preference for how I think it should look, but you can ignore that so long as they're consistent with each other

I can make them consistent, but could you provide more details on how you see them as inconsistent?

Can we pull the comparison up into a separate variable here too? Additionally, this line is getting long, I'd rather we break it up into 3 separate lines like we do in the below addition.

Yes to both of these, I'll make the change.

[wilbaker]

@nickgra I think I've addressed this feedback with my latest commit, but let me know if there's still changes you'd like to see.