Add ember-precompile

Adds a configuration file to use the ember-precompile filter.
Added defines parameter to uglifyjs & ugligyjs2 services
Merge pull request #244 from shouze/feature/uglifyJS2/AddDefineOption

Added defines parameter to uglifyjs & ugligyjs2 services
Added support for logging twig templates with an error
Merge pull request #281 from hason/twigloader

Added support for logging twig templates with an error
Proper management of the router resource type

Fixes #289

This is a workaround while waiting for
https://github.com/symfony/symfony/issues/11018
Merge pull request #290 from lavoiesl/router-resource-type

Proper management of the router resource type
Use PSR-4
Merge pull request #291 from Tobion/psr-4

Use PSR-4
Merge pull request #187 from Blackshawk/master

Add ember-precompile support
Fixed tests and removed useless dev requirements