Move profiler code from util into a new crate profile.

- Most of util::memory has been moved into profile::mem, though the
  `SizeOf` trait and related things remain in util::memory. The
  `SystemMemoryReporter` code is now in a submodule
  profile::mem::system_reporter.

- util::time has been moved entirely into profile::time.

components/profile/Cargo.toml

@@ -0,0 +1,20 @@
+[package]
+name = "profile"
+version = "0.0.1"
+authors = ["The Servo Project Developers"]
+
+[lib]
+name = "profile"
+path = "lib.rs"
+
+[dependencies.task_info]
+path = "../../support/rust-task_info"
+
+[dependencies.util]
+path = "../util"
+
+[dependencies]
+libc = "*"
+regex = "0.1.14"
+time = "0.1.12"
+url = "0.2.16"