Check for build number changed besides version change

[qunying]

It seems sbocheck currently does not honor the changed of same version but different build number in SlackBuild.org. Sometimes, it will failed to build a program due to its dependency rely on a new build of another package, which only have build number change.

For example, for this week's mixxxx, it failed to build on my machine, because I have a previous gtest pkg installed, but not the latest build. sbocheck does not pick up the new gtest build as version check passed and consider gtest already installed.