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
Add preFileDownload event on package.json fetch
don't require the error message have the first line of HTTP output in it
Merge pull request #2435 from ptarjan/master

don't require the error message have the first line of HTTP output in it
[CreateProject] allowed pretty version constraint
Cache in VersionConstraint
Merge pull request #2431 from bamarni/create-project-pretty-constraint

[CreateProject] allowed pretty constraint
Merge remote-tracking branch 'AlexeyKupershtokh/cache-version-constraint'
Rename a few things
Merge pull request #2434 from JJK801/extend-pre-file-download

Add preFileDownload event on packages.json fetch