Semantic versioning

[stevesims]

See breakintoprogram/agon-vdp#125 for commentary on the "why". :grin:

move version info out to version.h file

version info now a semantic version, with major, minor, patch, and “candidate” info, as well as an indicator for candidate type (displayed if candidate number is non-zero)

support for showing an automatically-generated build number added, which can be provided by a build script and is intended to be derived from the git hash

with this approach it should also be possible in the future to add other tooling to automatically increment version numbers

version info also includes the codebase variant, allowing us to easily differentiate between Quark and Console8

[breakintoprogram]

I'll switch to this after 1.04 has been released properly, save confusing everyone (including myself)