feature #718 install assets as symlink (Tobion)

This PR was merged into the 2.6-dev branch.

Discussion
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install assets as symlink

This is now safe because it will fallback to hard copies since symfony 2.6.

Commits
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3b5f195 install assets as relative symlinks

Author: fabpot

composer.json

@@ -49,6 +49,7 @@
     "extra": {
         "symfony-app-dir": "app",
         "symfony-web-dir": "web",
+        "symfony-assets-install": "relative",
         "incenteev-parameters": {
             "file": "app/config/parameters.yml"
         },