Resolves #2521. First and simple attempt to make a gzip downloader
There is no need in DIRECTORY_SEPARATOR since it Unix
Final fix. Preserve initial file name
Since there is no solution for non-unix (for now), remove the condition
Fallback to gzip functions when on Windows
Added `path` flag to show install path for installed packages
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Merge pull request #2765 from neoascetic/gzip_downloader

Gzip downloader (resolves #2521)
Merge remote-tracking branch 'alebiavati/list-paths'
Added a failing test for #2626
fix "replace-alias.test" test
for AliasPackages check that the aliased package is white listed so that version constraints of AliasPackages are taken into account when computing package provisions
Merge pull request #2805 from xabbuh/issue-2626

Check the referenced package for a white list entry