Adds special identifiers

Logically and as seen in the wild, pre-release version generally have special meaning.

Examples:

* v1.0.0-alpha takes precedence over v1.0.0-feature-a. 
* v1.0.0-rc.1 takes precedence over v1.0.0-testing-something
* v1.0.0-beta.1 takes precedence over v1.0.0-dev