Update precise, trusty, utopic, vivid, wily to landscape-client 15.06

Landscape Client 15.06 has been released. We would like to get these changes into precise, trusty, utopic, vivid and wily.

As far as released version of Ubuntu are concerned, the required pieces of information for the needed SRU follow (as laid out in the "Procedure" section of https://wiki.ubuntu.com/StableReleaseUpdates).

=== Statement explaining the impact ===

This release sports both bug-fixes and new features and we would like to make sure all of our supported customers (even those on lucid, precise, trusty and utopic) have access to these improvements. The notable ones are:

  - Fix container detection on Vivid hosts. (LP: #1449920)
  - Don't retry package operations if a SystemError is raised.
    (LP: #1444826)
  - Retry apt-get update when error 100 is returned. (LP: #1398090)
  - Better SSL error messages. (LP: #1409700)
  - Internal refactoring for better SSL user experience in the future.
    (LP: #1434546, LP: #1429888, LP: #1428826)

For more details see the aforementioned bugs (all mentioned in the debian/changelog of the proposed packages).

=== How the bug has been addressed ===

We have been following the development procedure laid out in https://wiki.ubuntu.com/LandscapeUpdates

Furthermore, the testing procedure results can be seen in
https://wiki.canonical.com/Landscape/ClientSRUTests/15.06

=== Patches ===

Branches allowing to recreate tested packages are attached to this bug report. A simple "debuild" should be possible once checked out.

=== Detailed instructions how to reproduce the bug ===

N/A

=== Discussion ===

All the source packages have been subject to the QA process detailed in the LandscapeUpdates document linked above.