check already exists, but no tests for it

fixes #78

Sexp#line can be used to retrieve or set the line number. No need to
invalidate the hash cache if line is not being set.

and get a free performance boost, yay!

just like Sexp#line(line)

also fixes issue with sometimes returning hash inside hash

because the next RubyParser release is going to break a LOT of stuff.

when target is a model

when rendering and when dealing with filters

This belongs in the annotations branch

This reverts commit fafdac24a03b97fe22d74065739bf3a69153b1a8.

Treat render :layout in views like partials

Fixes #69

Thanks @antage

Support multiple output files with different formats