Use 7-zip for parallel compression

Since we have a 7-zip dependency, use that to take advantage of multi-core systems to speed up build time a little.
Wintools-builder: co-locate path testing with zip

Put test and zip steps together instead of bulk zip then test
Use 7-zip for parallel compression

Since we have a 7-zip dependency, use that to take advantage of multi-core systems to speed up build time a little.
Merge branch 'master' of https://github.com/pearsonk/openxt
Merge pull request #25 from pearsonk/master

Use 7-zip for parallel compression