RTC: Fix system time initialization when using an exernal RTC.  Fix some bugs in the DS1307/DS3231 RTC driver

drivers/mtd/smart.c  Fixed SmartFS wear level error that occurs when the logical sector size is too small to save all wear level status bytes in a single sector.  Logical sectors 1 and 2 were simply not being allocated and then the read_sector and write_sector routines were failing.  From Ken Petit

stdio: Define BUFSIZ

stdlib: Fix forgotten FARs

atoi(): Cast return value to int

Fixed ms58xx sensor

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

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