Type testing functions plus initial JSE testing framework.
Correct documentation error.
Fix bug in assertErrorsExpectMore
Fix bug in assertErrorsExpectMore
Messed up trying to do an amended commit.
Fixed confusion around how eden.error works, plus improved assertErrors/assertErrorsExpectMore to accept an expected number of errors raised.
Added assertChecksNumberOfArgs and dependent funcs.
Make fatal errors re-enable error reporting.
Refine assertChecksNumberOfArgs
Added ability to 99.9% distinguish between func and proc *values* plus add missing file
Merge pull request #26 from ElizabethHudnott/Improve-type-casting,-type-testing,-etc

Improve type casting, type testing, etc
Remove 'old' canvas plugin.
Unify include to support js and jse.

* include is now async for JSE files.
* include now works for arbitrary urls through a JSONP proxy.
* include and execute are now a keywords.
* includeJS keyword removed.
* Generated JS may yield for includes, now executes a callback to signal termination.
* executeFile* functions have now been removed.
* include_js function has been removed.