In recent commits, HackMyResume generation logic, much like the pilots
in Top Gun who became too reliant on air-to-air missiles and lost the
true art of dogfighting, has become dependent on file-based generation
as implicit file assumptions have crept in. This commit reaffirms the
file-less, string-based nature of the generation process and, as a side
effect, adjusts the behavior of (binary) PDF generation to match.
Helpers shouldn't be specific to a given template engine (eg,
Handlebars) in order to allow sharing of helpers between different
template engines. Isolate abstract helpers in another module and apply
them via Handlebars.registerHelper and as necessary for other template
engines.
