Read/parse files up front

and cleanup reading/parsing files in general.

This will change some warnings, as sorting of files when processing has been fixed.

Also parse error message have changed a little bit, from something like
```json
{"error"=>"(string):11 :: parse error on value \"}\" (tRCURLY)",
 "location"=>
  "could not parse /storage/repos/canvas-lms/app/views/terms/_timespan.html.erb"}
```
to
```json
{"error"=>
  "/storage/repos/canvas-lms/app/views/terms/_timespan.html.erb:11 :: parse error on value \"}\" (tRCURLY)",
 "location"=>
  "Could not parse /storage/repos/canvas-lms/app/views/terms/_timespan.html.erb"}
```