improve debian version handling in debian package builder

[yxqd]

for the purpose of creating deb for different debian versions, the package root cmake file have to be updated and committed, pushed to github. although the only change is one line like this:

set(DOCKER_PKGING_DEB_DIST_VERSION "14.04")

, it is still not desired.

[yxqd]

It now supports setting DOCKER_PKGING_DEB_DIST_NAME and DOCKER_PKGING_DEB_DIST_VERSION using command line. Both need to supplied at the same time explicitly, otherwise the default value will be used.

Need to update all packages using this.