Kyle_HW6

This program takes an integer input 'n' and file <filename>.
It prints the first n primes to <filename>.  It also prints
the execution time and final prime to the standard output.

EXAMPLE

> ./kyle_hw6 5 file
last prime: 11
Time elapsed: 0.000000
> cat file
2
3
5
7
11
>

VALIDATION

There is only rudimentary user input validation, so please
make sure that your integer input is actually a positive
integer and that you have specified a reasonably named
output file.

BUGS

Very large integers (such as 10,000,000) cause a
segmentation fault.  Smaller integers such as 1000000 take a
very long time to run.