Fix BC break in 3.5.0 release

Merging develop to master for new release

add php 7.0 to travis manifest

Added docs to repository

Updated changelog and travis-ci setting

Added support for facet.contains and facet.contains.ignoreCase

Fix and improve PHAR generator

# Conflicts:
#	library/Solarium/Core/Client/Adapter/Curl.php
#	library/Solarium/QueryType/Select/Query/Component/Facet/Field.php
#	library/Solarium/QueryType/Select/Query/Component/FacetSet.php

Refactored unittest

# Conflicts:
#	phar/stub.php

By forcing the root with a leading slash, it avoids Git to look up
inside the whole tree of files.

Since the PHAR includes dependencies, we must use Composer's autoloader.
It ensures all dependencies will be loaded correctly and as expected.

Since Solarium has dependencies, this is more interesting to include
vendors (aka dependencies) inside the PHAR file.

Thus we include the `library/` directory with the `vendor/` directory.

`__halt_compiler` does not exist. This is `__HALT_COMPILER`.

The `Solarium_Autoloader` class is now `Solarium\Autoloader`. The
`Solarium_Version` class does no longer exist and
`Solarium\Client::VERSION` must be used instead.

[WIP] Fea/client interface

Improvements based on SensioLabs Insight analysis