# key is a single line from a file, which could be very long, such as whole book.
# value is empty in this case, since this is the first mapper function
# we are applying.
#
function mapper(key, value)
	1) Create a dictionary or hash table called counts
	(the keys in counts will be words found and the values will be counts of each word)

	2) Take the key argument to this function, which is the line of text, and split it on whitespace
	
	3) For every word resulting from the split key line:
			strip puntuation from the word
			convert the word to lowercase
			if the word is already a key in the counts dictionary, then
				increment the value in the counts dictioanry by one
			else
				add the key, value pair of (word, 1) to the counts dictionary

	4) For every word 'key' now in the dictionary
			'emit' the (word, count) to the system for the reducers to handle