Fix issue where none root composer.json could be used by ArtifactRepository http://www.php.net/manual/en/ziparchive.locatename.php#85512
Improved variable name.
Package should have download options
Package options must be passed as argument to downloader
Package options should be dumped if exists
Package options must be a non mandatory array and should be loaded when
exists
Repository options must be replicated on package when dist file is under
repository base dir
Improved the handling of trunkPath

- $this->baseUrl is only used if $this->trunkPath === false, otherwise
we will use $this->baseUrl with $this->trunkPath.
- scanning through trunkPath will now look for composer.json file
instead of a path that matches $this->trunkPath, beacuse checking
against the latter failed with deeper trunkPaths
- $this->rootIdentifier is now 'trunk' no matter how deep
$this->trunkPath is (with deeper trunkPaths, the name became something
like "dev-trunk-devel-team-packages-package"
Fixed a coding style issue

Missing a space between if and (
Add a warning for unbound constraints in the validating loader

Closes #2165
Added a new FAQ entry about unbound version constraints
Fix cache directory upgrading - do not try to remove the destination directory.
Composer supports four types.
Merge pull request #2405 from discordier/fix-upgrade-cache

Fix cache directory upgrading - do not try to (re)move the active cache dir.
Merge pull request #2406 from websafe/patch-1

Composer supports four types.
Add stronger warning in docs about #<ref> hack, refs #2410
If installer sets prefer option to false, the manager should too. Fixes #2359
Minor typo fix

introduced from 6ce0bf7cbf5edc622a8ccfbca226ffc825ca699e with #2314
Merge pull request #2414 from matthieuauger/fix/2359/config-option-overwrite-cli

If installer sets prefer to false, the manager should too. Fixes #2359
Merge pull request #2417 from glensc/patch-2

Minor typo fix