zap wildcard imports

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/compress/trunk@1647623 13f79535-47bb-0310-9956-ffa450edef68
record @krosenvold's changes for COMPRESS-295

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/compress/trunk@1647626 13f79535-47bb-0310-9956-ffa450edef68
Added testcase
All ok now
Second benchmark
Added a bunch of header field constants
Renamed methods