Deprecate (and remove?) the "relative" option

[webketje]

The relative: true option

will also duplicate sibling files so that relative links like css/style.css will be preserved nicely.

This sounds cool for enabling relative path intellisense for a single post, but results in n time duplication of an asset for every html file in a parent directory. That is an unacceptable bad practice that doesn't justify the benefit.
The folder strategy: to be analyzed if it provides sufficient added value.

Personally, I've never used permalinks with relative: true and rather use root-/baseurl-relative paths.

The removal consists of:

1. Making relative: false the default
2. Deprecating the relative option
3. Removing it altogether