`toYaml` utilized by `.Files` was introducing a new line. It is an issue since the new line is part of a functions output, it can't be whitespace chomped away so it would require a `trimSuffix "\n"` pipe. This commit trims one trailing `\n` from the toYaml output.

This fixes a TOML panic by replacing one parser library with another.
The older library did not gracefully handle reflection issues, and so
was prone to panic. The new one is not great, but it doesn't seem to
panic.

Closes #2271

This adds a fromYaml template function.

Closes #1604

This changes "pkg/chartutil".Files.Get to return a string, removes
"pkg/chartutil".Files.GetString, and adds
"pkg/chartutil".Files.GetBytes.

Closes #1020

Templates can now access the non-template files in a chart by using
the '{{.Files}}' map inside of a template.

Relates to #950