updated readme. fixes #14
changed fontfamily in demo and modal. fixes #15
updated options info
added close button to modal. also added key listener (press esc to close modal). fixes #13
added close button image
fixed demo img path for live and dev demo
added link to demo page
cleaned up main script.
updated readme for new script usage instructions
Merge pull request #17 from curlee/master

Fixes 3 issues