Phase 1 of repo reorg (#719)

* Remove unneeded script

* Rename Substrate Demo -> Substrate

* Rename demo -> node

* Build wasm from last rename.

* Merge ed25519 into substrate-primitives

* Minor tweak

* Rename substrate -> core

* Move substrate-runtime-support to core/runtime/support

* Rename/move substrate-runtime-version

* Move codec up a level

* Rename substrate-codec -> parity-codec

* Move environmental up a level

* Move pwasm-* up to top, ready for removal

* Remove requirement of s-r-support from s-r-primitives

* Move core/runtime/primitives into core/runtime-primitives

* Remove s-r-support dep from s-r-version

* Remove dep of s-r-support from bft

* Remove dep of s-r-support from node/consensus

* Sever all other core deps from s-r-support

* Forgot the no_std directive

* Rename non-SRML modules to sr-* to avoid match clashes

* Move runtime/* to srml/*

* Rename substrate-runtime-* -> srml-*

* Move srml to top-level

substrate/pwasm-libc/src/lib.rs

@@ -0,0 +1,55 @@
+#![warn(missing_docs)]
+#![cfg_attr(feature = "strict", deny(warnings))]
+#![no_std]
+
+// tag::description[]
+//! libc externs crate
+// end::description[]
+
+extern "C" {
+	fn ext_memcpy(dest: *mut u8, src: *const u8, n: usize) -> *mut u8;
+	fn ext_memmove(dest: *mut u8, src: *const u8, n: usize) -> *mut u8;
+	fn ext_memset(dest: *mut u8, c: i32, n: usize) -> *mut u8;
+	fn ext_memcmp(s1: *const u8, s2: *const u8, n: usize) -> i32;
+	fn ext_malloc(size: usize) -> *mut u8;
+	fn ext_free(ptr: *mut u8);
+}
+
+// Declaring these function here prevents Emscripten from including it's own verisons
+// into final binary.
+
+/// memcpy extern
+#[no_mangle]
+pub unsafe extern "C" fn memcpy(dest: *mut u8, src: *const u8, n: usize) -> *mut u8 {
+	ext_memcpy(dest, src, n)
+}
+
+/// memcmp extern
+#[no_mangle]
+pub unsafe extern "C" fn memcmp(s1: *const u8, s2: *const u8, n: usize) -> i32 {
+	ext_memcmp(s1, s2, n)
+}
+
+/// memmove extern
+#[no_mangle]
+pub unsafe extern "C" fn memmove(dest: *mut u8, src: *const u8, n: usize) -> *mut u8 {
+	ext_memmove(dest, src, n)
+}
+
+/// memset extern
+#[no_mangle]
+pub unsafe extern "C" fn memset(dest: *mut u8, c: i32, n: usize) -> *mut u8 {
+	ext_memset(dest, c, n)
+}
+
+/// malloc extern
+#[no_mangle]
+pub unsafe extern "C" fn malloc(size: usize) -> *mut u8 {
+	ext_malloc(size)
+}
+
+/// free extern
+#[no_mangle]
+pub unsafe extern "C" fn free(ptr: *mut u8) {
+	ext_free(ptr);
+}