Merge pull request #28 from LouTerrailloune/fix-nowebroot-2

Removed webRoot logic outside controller
minor tweaks to the README
made it possible to register multiple data loaders and pick a data loader on a per filter set basis (fixes #30)

this is a BC break for anyone that currently has a custom data loader or controller
renamed webRoot to rootPath (related to #7)
added FilterConfiguration service to support dynamic filter configurations (fixes #31)
refactored cache handling to support per filter set cache resolver (fixes #33)
fix tests
fix service name
refactored cache layer to move some common code into the CacheManager (also fixes issues created by the fix for #33 for users that disable the cache but use the template helper)
cosmetics
Extracted the abstract class Resolver from WebPathResolver
Merge pull request #34 from lenar/patch-1

fix service name
ensure all services are prefixed properly
Corrected config example in the doc for the custom cache resolver
fix per filter set cache handling (fixes #36)
cosmetics
Renamed the abstract class Resolver to AbstractFilesystemResolver, Removed the CacheManager injection from AbstractFilesystemResolver
Merge pull request #35 from sixty-nine/master

Extracted the abstract class Resolver from WebPathResolver
Forgot to rename the Imagine/Cache/Resolver.php file to reflect the new class name
Add Resize and RelativeResize filters

Ported these over from JmikolaImagineBundle, with some modifications to accomodate LiipImagineBundle's LoaderInterface. These can potentially replace the existing Thumbnail filter.