Define 'releasenumber' macro in spec file

- Define 'releasenumber' macro in spec file so that the release number
  only needs to be manually changed in one place, rather than two.
- Update version number for test build.
- Change 'Source0' to just 'Source' for tidyness as they are equivalent
  when there is only one source.
Merge pull request #9 from apel/spec-tidy

Spec file tidy up