* upstream/master: (98 commits)
Fallback to zlib extension to unpack gzip on non Windows systems
Zip extension does not provide zlib support
Unified all Windows tests throughout the code.
Added Platform utility and unit test for it.
Remove warnings for non-writable dirs, refs #3588
[doc] add -H flag to sudo commands
use full json content to determine reference, closes#4859
typos
Make sure COMPOSER_AUTH is also loaded in Config, refs #4546
Use proper defaults for IO authentications
Add verbosity input support to IOInterface
Update SolverTest.php
Update broken-deps-do-not-replace.test
Update SolverProblemsException.php
Cleaned up check+conversion that was no longer required.
Cleaner notation for expected exceptions in fixtures.
Introduced more generic, less invasive way to test for exceptions in fixtures, more in line with how phpunit works.
Included unit test for circular root dependencies.
Expanded InstallerTest to support expecting Exceptions by supplying "EXCEPTION" as "--EXPECT--"
Clarified error message and added braces.
...
The command allows to slightly change how repository updates are handled during install
In the previous version composer failed to updated if .git|.svn|.hg folder was missing from the package
In the current version, with the option enabled, if the update fails for exactly this reason,
it'll try to remove the package completely and install it from remote
which checks if vcs metadata is present in the package
Fixed a bug with -vvv mode. When .git folder is missing from package
in normal mode, -v mode, -vv mode the program throws the exception about missing .git folder
in -vvv mode an exception about inability to read logs