Added a lower-half timer driver for stm32 which is compatible with the upper-half driver located at /drivers/timers/timer.c

If multiple AT24xx devices are supported and resources are allocated, then it may also be necessary to free those resource

Pca9555 interrupt support.

Currently using a signal, and a single notified task.
signal handling support moved to generic IO expander header (not pca specific)

Move rivers/wireless/cc3000/security.c to crypto/aes.c; move include/nuttx/wireless/cc3000/security.h to include/nuttx/crypto/aes.h

CAN Kconfig: Resolve a circular dependency.  I am not sure if the correct version foolproof, however

CAN driver: Removing call to can_xmit() from can_txready() in a previous commit was a mistake.  This commit restores the call to can_xmit(), but does the call in a safer environment on the work thread.

binfmt: Cosmetic -- rename binfmt_internal.h to binfmt.h.  Move related argument copy logic into new file, binfmt_copyargv.c

drivers/mtd/mtd_progmem.c: Add an upper-half driver that can be used with any FLASH library that provides the itnerfaces defined in include/nuttx/progmem.h

CAN: Don't disable TX interrupts if the S/W TX FIFO is empty but the hardware supports a H/W TX FIFO

MTD Smart: Remove checks for 64KB erase block size.  erasesize was changed to 32-bits in struct mtd_geometry_s

SmartFS: Backout last change.  It alters the behavior when it should not.  Obviously there is something that I do not understand

s25fl1: When unprotecting, handle case where protection bits are inverted.  Add option to s25flinitilize() to unprotected on power up