net/:  Change some *err() message to *info() messages if what was a *dbg() message does not indicate and error condition.

fs/:  Change some *err() message to *info() messages if what was a *dbg() message does not indicate and error condition.

sched/:  Change some *err() message to *info() messages if what was a *dbg() message does not indicate and error condition.

Button upper half driver:  Add definitions needed for compilation with the poll() interface is not disabled.

kinetis pwm support

Correct the can2 rx irq number for stm32f10xx chips

crc64: fix error

already prototyped in kinetis.h. It is enabled when CONFIG_DEBUG_GPIO
is defined.

libc/misc: add crc64

crc16: fix error

Fix compilation errors in debug mode of stm32_pwm.c

Networking:  In both IPv6 and IPv4 incoming logic:  (1) Should check if the packet size is large enough before trying to access the packet length in the IP header.  (2) In the comparison between the IP length and the full packet length, need to subtract the size of the link layer header before making the comparison or we will get false positives (i.e., the packet is really too small).

Initial commit. Compile checked only.