Minor update, forgot to make use of num_words() in str_cww()

This includes my_str.c and my_str.h which introduce str_cew, str_cww, and num_words.

str_cew: Capitalize the first letter of every word in a space delimited string.
str_cww: Capitalize an entire word in a string determined by position parameter
num_words: Count the number of words in a string delimited by either any non-alpha character, or spaces.

If you have suggestions on improving these functions please PM me here, my username is ralgith.