Improve --help message and Fix -e/--eval switch

--help should at least give some hint that node takes the -e switch

Update help message to include -e and swap eval block with module load block so argv works correctly

[steve@sane node](master)$ ./node -e 'process.argv' foo bar
[ '/home/steve/code/node/node', 'foo', 'bar' ]

:)

Add simple test for -e option.

Fixes #1311.