Rename the packages and classes in the Run Selector plugin.
The following changes should be made:

• rename the root package to org.jenkinsci.plugins.runselector
• rename the BuildSelector to RunSelector (as well as all of its implementations and parameter names)
• rename the BuildFilter to RunFilter (as well as all of its implementations and parameter names)
• move all RunSelector implementations under org.jenkinsci.plugins.runselector.selectors package
• move all RunFIlter implementations under org.jenkinsci.plugins.runselector.filters package
• rename CopyArtifact*Context to RunSelector*Context