Generate an APC prefix based on __FILE__

Closes #654
fixed version in composer.json
updated version to 2.6
bumping SensioDistributionBundle dep
bumping Symfony to 2.5 stable
fixed symfony deps
fixed symfony deps
License year range updated
Ignore phpunit.xml

...as recommended in http://symfony.com/doc/current/book/testing.html#phpunit-configuration
updated PHPUnit configuration (added XSD, removed defaults, proper formatting)
minor #678 update PHPUnit configuration (add XSD, remove defaults, proper formatting) (craue)

This PR was merged into the 2.3 branch.

Discussion
----------

update PHPUnit configuration (add XSD, remove defaults, proper formatting)

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | --
| License       | MIT
| Doc PR        | --

See symfony/symfony#11344.

Commits
-------

324692e updated PHPUnit configuration (added XSD, removed defaults, proper formatting)
Merge branch '2.3' into 2.4

* 2.3:
  updated PHPUnit configuration (added XSD, removed defaults, proper formatting)
Merge branch '2.4' into 2.5

* 2.4:
  updated PHPUnit configuration (added XSD, removed defaults, proper formatting)
  fixed symfony deps

Conflicts:
	composer.json
Merge branch '2.5'

* 2.5:
  updated PHPUnit configuration (added XSD, removed defaults, proper formatting)
  fixed symfony deps
  fixed symfony deps
  bumping Symfony to 2.5 stable
  bumping SensioDistributionBundle dep

Conflicts:
	composer.json
minor #668 License year range updated (peterkokot)

This PR was merged into the 2.3 branch.

Discussion
----------

License year range updated

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | none
| License       | MIT
| Doc PR        | none

Commits
-------

c123286 License year range updated
Merge branch '2.3' into 2.4

* 2.3:
  License year range updated
Merge branch '2.4' into 2.5

* 2.4:
  License year range updated
Merge branch '2.5'

* 2.5:
  License year range updated
minor #663 Add phpunit.xml to .gitignore (nicwortel)

This PR was merged into the 2.6-dev branch.

Discussion
----------

Add phpunit.xml to .gitignore

[The documentation](http://symfony.com/doc/current/book/testing.html#phpunit-configuration) recommends ignoring `phpunit.xml`, and only committing `phpunit.xml.dist` in version control.

This PR adds `/app/phpunit.xml` to the `.gitignore` that comes with the Symfony Standard distribution.

Commits
-------

9053b6b Ignore phpunit.xml
updated VENDORS for 2.5.1