Added optional use of igbinary if installed
Update ServiceProvider.php
Added missing import
Update ProjectDescriptorMapper.php
Update ProjectDescriptorMapper.php

@mvriel This sounds strange to me because it is working on my project i had tests with. But if the project descriptor is not populated with data my first version just overwritten the cache with empty values then? so maybe it will be better to clear the cache if the value couldnot be unserialized. what do you think?
Update ProjectDescriptorMapper.php
Added statistics writer
Added statistics writer to service provider
No need for trim version - fixed in meantime
Added files counter
Update Extension.php

Fixes #1326
Added check for space in path
Added space check
Added check for space in path
Added check for space in path
changed RuntimeException to InvalidArgumentException
#1330: Fix crash when assembling package tags

In a recent refactoring we removed all notion of string based tags
but put them in TagDescriptors. Apparently I missed a bit of handling
of the package tags and this caused fatal errors later due to typehints.
Merge pull request #1334 from mvriel/feature/1330

#1330: Fix crash when assembling package tags
Fixed #1331, Argument/Param checking does not work

During changes in the last sprint the checking of arguments and
parameters was broken. This commit restores that functionality.
Added HHVM to travis.yml