Issue #1557094: Mimic PHP's rename(), by overwriting existing files.
Issue #1776852 by afeijo, q0rban: Add hook_requirements for allow_url_fopen.
Return early in hook_requirements if phase isn't runtime.
Root path should be indicated as a directory
Don't allow directories to be deleted unless they are empty. Adds a force option to help remove image styles
Issue #1783444 by mokitger: Fixed Default variable on settings form.