Typecasting environment variables

Environment variables bound in the config are type-casted to their expected type.

See #147

Fixing checkbox "fetch from environment" in config page

See #146

Invalidate opcache cache on install

This fixes install issues if the opcache.revalidate_freq is not set to 0 during the installation process.
See #145

Adding the ability to fetch config variable from environment

Very useful for integration with Docker based environments where config comes from environment variables.

Adds the possibility to alter a class name in the container

See #143

Fixing detection of classes in symlinked directories

Merge pull request #139 from marcteyssier/2.0

Fix mapping of symlink

Fixing error in PHP 7.1

Merge pull request #138 from toscan/patch-1

Fix php 7.1 notice

Minor improvement

Improved position of added services in the Mouf class.
See #137.
Credits to @dsavina

Bugfix release

Fixing a weird bug in autoload management with recent versions of Composer.

Bugfix release

Fixes PSR-11 implementation regarding behaviour of the NotFoundException.
Fixes class analysis when a constant from a non loadable class was encountered.