Hugo 0.20 broke some sites that grouped their blog post and images together in subfolders.
This commit re-introduces that behaviour:
* If the file base name resolves to the same as the base name for the output type (i.e. "index" for HTML), the user probably meant it, so we treat that as an `uglyURL`, i.e. `my-blog-post-1.md`=> `/my-blog-post-1/index.html`
* The main use case for this is to group blog post and images together.
* Note that for the top level folder there will be a potential name conflict with a `section` `index.html` (if enabled)
* This issue will not be relevant for subfolders in sections
* Hugo will soon add support for nested sections, but we will have to find a way to separate them from the rest (`/content/_mysubsection` maybe).
Fixes#3396
This is a pretty fundamental change in Hugo, but absolutely needed if we should have any hope of getting "multiple outputs" done.
This commit's goal is to say:
* Every file target path is created by `createTargetPath`, i.e. one function for all.
* That function takes every page and site parameter into account, to avoid fragile string parsing to uglify etc. later on.
* The path creation logic has full test coverage.
* All permalinks, paginator URLs etc. are then built on top of that same logic.
Fixes#1252Fixes#2110Closes#2374Fixes#1885Fixes#3102Fixes#3179Fixes#1641Fixes#1989
