Support custom version tag prefix #228
Description
Currently, it seems that GitVersion will only parse the version if it has no prefixes, i.e. 1.2.3, not v1.2.3.
It would be great if GitVersion supported common prefixes (mainly, v), as well as custom git-flow version prefixes (from config):
[gitflow "prefix"]
...
versiontag = Verz
...