Fix OpenCloud adapter exists always return false

Should fix #160
Update OpenCloud.php

Changed exists check condition
Merge pull request #161 from lmammino/fix-opencloud-exists

Fix OpenCloud adapter exists always return false
Make pecl install verbose to check what is falling at travis when
install ssh2-beta ext. to check what is falling at travis when install
ssh2-beta ext.
Remove sudo from pecl command runned at travis.
Marked RackspaceCloudfiles as depreciated and change repo in
composer.json so it will not fail.
Fixed Filesystem::listKeys
OpenCloud\ObjectStore > OpenCloud\ObjectStore\Service
Fix invalid Error-class import(s)
Merge pull request #172 from escapestudios/master

ObjectStore-method returns instance of OpenCloud\ObjectStore\Service
Escape forward slashes
Added phpseclib sftp adapter
Set S3 permissions during file write

I've added this since with GaufretteBundle you can't use AclAwareAmazonS3 and this would be a nice way to set file permissions on write.
Added acl into class options and acl getter/setter
Merge pull request #181 from nmpolo/regexfix

Escape forward slashes
Merge branch 'patch-1' of https://github.com/alex88/Gaufrette into alex88-patch-1
Add spec for acl handling in amazon adapter. Renaming of spec methods.
Merge pull request #174 from hason/phpseclib

Added phpseclib sftp adapter
Merge pull request #170 from hason/listKeys

Fixed Filesystem::listKeys
Updated phpspec for newest version. Migrate specs.