OHCI:  Fix length calculation in all OHCI drivers:  CBP==0 means that the entire buffer was transferred, not that a null packet was tranaferred

In go_os_start that sets the IDLE thread stack coloration, mov does not set condition codes which are tested by the following beq.  Need to use movs instead.  Noted by David Sidrane

 kl: enable the clocks to UART1 and UART2. The previous version would cause a hard fault on startup due to the modules not being clocked.  Also drop the GPIO configuration as it's done during kl_start().  From Michael Hope.

kl: fix PWM debugging. TPM1 and TPM2 have two channels instead of six and will hard fault if you try to read the missing channels.  From Michael Hope.

USB host CDC/ACM:  Add a bulk-only mode mostly for test, fix two bad assertions.  Correct some loop termination logic in RX data receipt

Misc improvements to the CDC/ACM host driver, mostly related to parsing the configuration descriptor.  Still does not work.

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).