Adds board support for the Teensy LC board.  Support is based off the Freedom KL25Z board. LED, PWM, and UART0 have been tested. The SPI pins are mapped correctly but have not yet been tested.  From Michael Hope as SourceForge patch 51.

Add support for the KL25Z64.  The KL25Z64 is a lower memory variant of the KL25Z128 and is used on the Teensy LC.  From Michael as SourceForge patch 50.

LPC17 USB host: Fix some compile errors when bulk endpoints + USB debug enabled.  Refresh a configuration

Rename usbhost_storageinit() to usbhost_msc_initialize().  Add calls to usbhost_cdcacm_initialize() is CONFIG_USBHOST_CDCACM is selected.

drivers/usbhost: Add initial implementatino of a host-side CDC/ACM driver.  Completely untested on initial commit (2015-05-06).

USB host:  More fixes from last changes.. MSC block read and write must again return number of blocks on success.  Fix numerous places where the assumption the ret == OK means success.  Since the transfer method now returns the number of byte transfered, the correct test for success is ret >= 0

USB host:  Modify the transfer() and asynch() methods so that the actual size of  the transfer is returned.  Unverified on initial commit.

SAMA5D OHCI: Remove a local variable that is unused when debug is disabled; refresh a configuration.  Update a README

Update some READMEs.  For all implementation of the USBHOST waiter, make sure that the waiter thread stack size is larger if the USB hub feature is enabled

Olimex LPC1766STK: The USB host waiter stack should be configurable because it needs to be a lot depending when using a hub

LPC31 and SAMA5Dx EHCI drivers: Fix cache related problem.  All buffers are now aligned with the cache line size in both starting address and in length.  This cause major problems in unlucky builds where the USB host buffers where unaligned and abbutting other data.  The cache flush and invalidate operations could be subverted by acceses to adjacent data or could have unexpected side effects.  This bug has been in the ECHI drivers forever, but was only revealed due to unlucky memory allocations during the integration of the hub feature.

USB host: If the implementation of the disconnect method frees the EP0 endpoint, then it must nullify it in the port structure