Modify format of debug output for improved readability.

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>
pim.c: Whitespace cleanup.

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>
pim.c: Refactor send_raw_ip() and send_fragment() --> send_frame()

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>