Ignore whitespace between comment and hash

[daniel-white]

I had a problem where my declarations didn't have whitespace:

//#if process.env.NODE_ENV !== 'production'
...
//#endif

It would be nice if the whitespace between // and # could be ignored.

[perf2711]

This problem also happened in my code. Removing the spaces fixed the problem.
However, in the README the conditionals are clearly written with a space before them.
So, if even this cannot be changed, at least it would be nice to update the README.