Update HC4 to latest.

That contains among many bugfixes contains
the fix for HTTPCLIENT-1448 too.
NEXUS-6271: Make Tika recognize empty ZIP file and UT

The test renamed back to UT from IT, as it was chatty with MimeUtil2
in place but now with Tika is not and is fast.
Merge pull request #376 from sonatype/update-hc4

Update HC4 to latest
Merge pull request #378 from sonatype/NEXUS-6271-empty-zip

NEXUS-6271: Make Tika recognize empty ZIP file and UT
[NX-213] Normalize download stuff, move common bits to wonderland
[NX-213] Ensure we create/download files from downloads directory (direct children)
Add plugin identity component for kazuki and log kazuki version
[NX-213] Additional logging
Merge pull request #382 from sonatype/NX-213-normalize-download

REVIEW: [NX-213] Normalize download stuff, move common bits to wonderland
Merge remote-tracking branch 'origin/master' into rapture