Introduce use-dependency amalgamation. We now have:

- `use standard;` (bring in a set of standard and external dependencies)
- `use common;` (bring in a low-level subset of this crate; basically anything that itself requires only `use standard;`)

And, from an external create:
- `use ethcore_util::*;` (bring in the entirety of this module and the standard dependencies)

src/common.rs

@@ -0,0 +1,7 @@
+pub use standard::*;
+pub use error::*;
+pub use hash::*;
+pub use uint::*;
+pub use bytes::*;
+pub use vector::*;
+pub use sha3::*;

src/lib.rs

@@ -48,6 +48,8 @@ extern crate secp256k1;
 extern crate arrayvec;
 extern crate elastic_array;
 
+pub mod standard;
+pub mod common;
 pub mod error;
 pub mod hash;
 pub mod uint;
@@ -68,4 +70,19 @@ pub mod heapsizeof;
 pub mod squeeze;
 pub mod semantic_version;
 
+pub use common::*;
+pub use rlp::*;
+pub use hashdb::*;
+pub use memorydb::*;
+pub use overlaydb::*;
+pub use math::*;
+pub use chainfilter::*;
+pub use crypto::*;
+pub use triehash::*;
+pub use trie::*;
+pub use nibbleslice::*;
+pub use heapsizeof::*;
+pub use squeeze::*;
+pub use semantic_version::*;
+
 //pub mod network;

src/rlp/mod.rs

@@ -32,7 +32,7 @@
 
 pub mod rlptraits;
 pub mod rlperrors;
-pub mod rlp;
+pub mod rlpin;
 pub mod untrusted_rlp;
 pub mod rlpstream;
 
@@ -42,7 +42,7 @@ mod tests;
 pub use self::rlperrors::DecoderError;
 pub use self::rlptraits::{Decoder, Decodable, View, Stream, Encodable, Encoder};
 pub use self::untrusted_rlp::{UntrustedRlp, UntrustedRlpIterator, PayloadInfo, Prototype};
-pub use self::rlp::{Rlp, RlpIterator};
+pub use self::rlpin::{Rlp, RlpIterator};
 pub use self::rlpstream::{RlpStream};
 use super::hash::H256;
 

src/standard.rs

@@ -0,0 +1,21 @@
+pub use std::io;
+pub use std::str;
+pub use std::fmt;
+pub use std::slice;
+
+pub use std::path::Path;
+pub use std::str::{FromStr};
+pub use std::io::{Read,Write};
+pub use std::hash::{Hash, Hasher};
+pub use std::error::Error as StdError;
+
+pub use std::ops::*;
+pub use std::cmp::*;
+pub use std::cell::*;
+pub use std::collections::*;
+
+pub use rustc_serialize::json::Json;
+pub use rustc_serialize::base64::FromBase64;
+pub use rustc_serialize::hex::FromHex;
+
+pub use heapsize::HeapSizeOf;