Initial work on ES6 modules
More modularization
Building an AMD file
Further progress towards modularization.

At this point, I have only 2 fails in the Node build, but I'm doing a
bunch of manual stuff locally and still have a bunch of hacks.
Make the Handlebars environment into an object

The idea is that the environment wraps up the mutable stuff in
Handlebars (like the helpers) and that you could theoretically create a
new one at any time and pass it in to Handlebars.template.

Every test makes a new environment and uses it in template compilation.
Move more testing mutations into the environment
Global Handlebars.compile uses its env

The basic strategy is that there will be a global Handlebars object for
the browser build, and that object will have a `compile` on it which
uses its environment in the compiler.

It will also be possible to glue things together manually by using the
AMD build and passing the environment to `compile` directly. Some of
these details are TBD.
Remove unused var
Simplify inverse only block case
Improve uglify compression
adds Assemble and handlebars-helpers projects to "Handlebars in the Wild" section of README. Bullets are now ordered alphabetically
Merge pull request #594 from assemble/master

adds Assemble and handlebars-helpers projects to README
Update external url
Fix #597. If-helper doesn't anymore consider 0 as falsy value.
Use the ('' + string) form of string coercion

Using string.toString() will throw errors in current versions of Safari
(6.0.5 currently) for some values. The error is a particularly cryptic
"Type Error: type error", which no indication as to the value that
caused the error. By using the '' + string form of coercion the error
doesn't seem to occur.

Depending on the browser used there is a sizable performance increase
in using the concatenation form of coercion. In instances where there
is not a performance improvement (i.e. Firefox), the speed difference
is entirely negligable. See: http://jsperf.com/convert-to-string-bj/3
Merge pull request #535 from sorentwo/alternate-string-coercion

Use the String(string) form of string coercion
Merge branch 'master' of github.com:artiee/handlebars.js into artiee-master
Add test case
Rebuild
Update release notes