The path to process.
True if s doesn't start with slash and doesn't include colon and double slash.
pc.path.isRelativePath("file.txt"); // returns true
pc.path.isRelativePath("path/to/file.txt"); // returns true
pc.path.isRelativePath("./path/to/file.txt"); // returns true
pc.path.isRelativePath("../path/to/file.jpg"); // returns true
pc.path.isRelativePath("/path/to/file.jpg"); // returns false
pc.path.isRelativePath("http://path/to/file.jpg"); // returns false
Check if a string s is relative path.