Light cleanup to a little bit of InputCommon. Replaces much of the iterators that litter this section of the codebase.

Also clean up a little bit of the comments that describe the interface classes.
Remove some unnecessary comments, as pointed out by Matt_P.
Introduce the usage of unique_ptr into the InputCommon ControlEmu.h class. Allows for the automatic handling of resource deallocation.
Clean up InputConfigDiag.cpp.

Changes a bunch of for+iterator loops into foreach loops.
Purely stylistic cleanup of Core/HW/WiimoteEmu/Attachment/* files.

Also cleaned up WiimoteEmu.h as well.
Merge pull request #23 from lioncash/sorta-large-input-cleanup

Larger cleanup to input-related source files (this time using unique_ptr).