Improves readability of error messages, and fixes some bugs

[conordickinson]

In jsdoc2betterjs:

• Use function name from @method, @function, and @func jsdoc tags.
• Fix for crash on tag lines that don't match the regex.
• Provide tag line string in malformed tag exception.

In function strong type checking:

• Include function name in error message
• Convert type and value to user-friendly type names in error message
• Fix for error message displaying arguments[i] instead of args[i]

[conordickinson]

@jeromeetienne : I updated this with unit tests.