Wrap code in an instance_eval context for syntax check.

This evaluates the code in a context similar to what Chef does when
compiling recipes, so that idioms like using `return` to end evaluation
of a recipe will work.
Update
Merge branch 'CHEF-5199'
reorder middleware in chef::http::simple

the api here reverses the order of the reversed order in the
responses for some reason.  this broke remote_file for most of the
internet.
fix spec test

compared to the same test in rest_spec.rb this makes no sense at all
why we need to invert it, and its clear to me why this bug got through code
review because it looks obviously correct.  it looks very obviously
wrong now, but it works.
Merge pull request #1368 from opscode/lcg/CHEF-5198

reorder middleware in chef::http::simple