min-content and max-content are not prefixed

I wasn't understanding why my css declaration `max-width:min-content` wasn't working on Safari and I discovered that I had to add prefixes `-webkit-min-content` and `moz-min-content`.

I had to add all prefixes in a single css declaration like this:

`'max-width':'-moz-min-content; max-width:-webkit-min-content; max-width:min-content'`

The issue names no source file or test; start by locating Aphrodite's browser-prefixing entry point and the handling of min-content and max-content declarations. Verify that generated CSS includes the required vendor-prefixed fallbacks and add or run coverage for those declarations.

Written by the indexing model from the issue text.