removing starts_with() in favor of strpos()
Merge pull request #4221 from rstrong-pica9/hotfix_removeStartsWith

Undefined function "starts_with" in Illuminate/Container
Improved symfony security dependency
Merge pull request #4312 from GrahamCampbell/4.1-security

[4.1] Improved Symfony Security Dependency
Fix conflicts.
Migrate to stringy