swarm: plan bee for content storage and distribution on web3

This change imports the Swarm protocol codebase. Compared to the 'swarm'
branch, a few mostly cosmetic changes had to be made:

* The various redundant log message prefixes are gone.
* All files now have LGPLv3 license headers.
* Minor code changes were needed to please go vet and make the tests
  pass on Windows.
* Further changes were required to adapt to the go-ethereum develop
  branch and its new Go APIs.

Some code has not (yet) been brought over:

* swarm/cmd/bzzhash: will reappear as cmd/bzzhash later
* swarm/cmd/bzzup.sh: will be reimplemented in cmd/bzzup
* swarm/cmd/makegenesis: will reappear somehow
* swarm/examples/album: will move to a separate repository
* swarm/examples/filemanager: ditto
* swarm/examples/files: will not be merged
* swarm/test/*: will not be merged
* swarm/services/swear: will reappear as contracts/swear when needed

internal/web3ext/web3ext.go

@@ -18,17 +18,159 @@
 package web3ext
 
 var Modules = map[string]string{
-	"admin":    Admin_JS,
-	"debug":    Debug_JS,
-	"eth":      Eth_JS,
-	"miner":    Miner_JS,
-	"net":      Net_JS,
-	"personal": Personal_JS,
-	"rpc":      RPC_JS,
-	"shh":      Shh_JS,
-	"txpool":   TxPool_JS,
+	"admin":      Admin_JS,
+	"bzz":        Bzz_JS,
+	"chequebook": Chequebook_JS,
+	"debug":      Debug_JS,
+	"ens":        ENS_JS,
+	"eth":        Eth_JS,
+	"miner":      Miner_JS,
+	"net":        Net_JS,
+	"personal":   Personal_JS,
+	"rpc":        RPC_JS,
+	"shh":        Shh_JS,
+	"txpool":     TxPool_JS,
 }
 
+const Bzz_JS = `
+web3._extend({
+	property: 'bzz',
+	methods:
+	[
+		new web3._extend.Method({
+			name: 'blockNetworkRead',
+			call: 'bzz_blockNetworkRead',
+			params: 1,
+			inputFormatter: [null]
+		}),
+		new web3._extend.Method({
+			name: 'syncEnabled',
+			call: 'bzz_syncEnabled',
+			params: 1,
+			inputFormatter: [null]
+		}),
+		new web3._extend.Method({
+			name: 'swapEnabled',
+			call: 'bzz_swapEnabled',
+			params: 1,
+			inputFormatter: [null]
+		}),
+		new web3._extend.Method({
+			name: 'download',
+			call: 'bzz_download',
+			params: 2,
+			inputFormatter: [null, null]
+		}),
+		new web3._extend.Method({
+			name: 'upload',
+			call: 'bzz_upload',
+			params: 2,
+			inputFormatter: [null, null]
+		}),
+		new web3._extend.Method({
+			name: 'retrieve',
+			call: 'bzz_retrieve',
+			params: 1,
+			inputFormatter: [null]
+		}),
+		new web3._extend.Method({
+			name: 'store',
+			call: 'bzz_store',
+			params: 2,
+			inputFormatter: [null]
+		}),
+		new web3._extend.Method({
+			name: 'get',
+			call: 'bzz_get',
+			params: 1,
+			inputFormatter: [null]
+		}),
+		new web3._extend.Method({
+			name: 'put',
+			call: 'bzz_put',
+			params: 2,
+			inputFormatter: [null, null]
+		}),
+		new web3._extend.Method({
+			name: 'modify',
+			call: 'bzz_modify',
+			params: 4,
+			inputFormatter: [null, null, null, null]
+		})
+	],
+	properties:
+	[
+		new web3._extend.Property({
+			name: 'hive',
+			getter: 'bzz_hive'
+		}),
+		new web3._extend.Property({
+			name: 'info',
+			getter: 'bzz_info',
+		}),
+	]
+});
+`
+
+const ENS_JS = `
+web3._extend({
+  property: 'ens',
+  methods:
+  [
+    new web3._extend.Method({
+			name: 'register',
+			call: 'ens_register',
+			params: 1,
+			inputFormatter: [null]
+		}),
+	new web3._extend.Method({
+			name: 'setContentHash',
+			call: 'ens_setContentHash',
+			params: 2,
+			inputFormatter: [null, null]
+		}),
+	new web3._extend.Method({
+			name: 'resolve',
+			call: 'ens_resolve',
+			params: 1,
+			inputFormatter: [null]
+		}),
+	]
+})
+`
+
+const Chequebook_JS = `
+web3._extend({
+  property: 'chequebook',
+  methods:
+  [
+    new web3._extend.Method({
+      name: 'deposit',
+      call: 'chequebook_deposit',
+      params: 1,
+      inputFormatter: [null]
+    }),
+    new web3._extend.Property({
+			name: 'balance',
+			getter: 'chequebook_balance',
+				outputFormatter: web3._extend.utils.toDecimal
+		}),
+    new web3._extend.Method({
+      name: 'cash',
+      call: 'chequebook_cash',
+      params: 1,
+      inputFormatter: [null]
+    }),
+    new web3._extend.Method({
+      name: 'issue',
+      call: 'chequebook_issue',
+      params: 2,
+      inputFormatter: [null, null]
+    }),
+  ]
+});
+`
+
 const Admin_JS = `
 web3._extend({
 	property: 'admin',