fix #17

Update to 2017c

Fix #16

v6.1.3

6.1.3: fix #16

Fix #15

v6.1.2

6.1.2: fix #15

Fix #13

@pirxpilot noted a few locations that returned incorrect results. This release fixes that issue. In addition,

1. I added some comments to improve code documentation slightly.
2. I made rebuild.sh executable (not sure why I hadn't previously).

Support browser and node applications synchronously

This release changes the build process for the project such that it provides a synchronous interface in both the browser and in Node.JS.