Contract factories and bytecode introspection (#305)

* Support for CREATE, CLONE and BYTECODE_HASH

* Add missing files

* Pushed the clone example through the typechecker

* CLONE compiles

* Fix dependent type in CLONE

* Bytecode hash fixes

* Refactor

* Refactor 2

* move some logic away

* Fixed some error messages. Type inference of child contract still does some random shit\n(mistakes arguments with result type)

* CREATE sometimes compiles and sometimes not

* Fix some scoping/constraint issues

* works, needs cleanup

* cleanup

* Fix some tests. Remove optimization of singleton tuples

* Fix default argument for clone

* Cleanup

* CHANGELOG

* Mention void type

* Address review, fix some dialyzer errors

* Please dialyzer

* Fix failing tests

* Write negative tests

* Docs

* TOC

* missing 'the'

* missing 'the'

* missing 'the'

* missing 'the'

* mention pre-fund

* format

* pre-fund clarification

* format

* Grammar in docs

test/contracts/remote_call.aes

@@ -1,18 +1,18 @@
 
-contract Remote1 =
-  entrypoint main : (int) => int
+contract interface Remote1 =
+  entrypoint main_fun : (int) => int
 
-contract Remote2 =
+contract interface Remote2 =
   entrypoint call : (Remote1, int) => int
 
-contract Remote3 =
+contract interface Remote3 =
   entrypoint get : () => int
   entrypoint tick : () => unit
 
 contract RemoteCall =
 
     stateful entrypoint call(r : Remote1, x : int) : int =
-        r.main(gas = 10000, value = 10, x)
+        r.main_fun(gas = 10000, value = 10, x)
 
     entrypoint staged_call(r1 : Remote1, r2 : Remote2, x : int) =
         r2.call(r1, x)