preserve whitespace when preprocessing

[jenseng]

to facilitate debugging, we should preserve whitespace (or at least newlines) when converting a translate="yes" component to a <ComponentInterpolator> ... that way line numbers will match up with the original source. as it stands right now, recast is injecting some newlines, presumably for readability.

we handle this kinda rudimentarily in i18nliner (erb)

[jenseng]

this is slightly less critical, since we now share the same AST with i18nliner-js ... for i18nliner errors at least, the line numbers will be correct (since it uses the original loc.start)

that said, it's still nice to do for general js debugging