Changes in api and upwards

- Removed out-of-stack error reporting
- Revised module system to match previous Orchid system
- Errors are now in a Vec everywhere
- Implemented atoms and lexer
- Started implementation of line parser
- Tree is now ephemeral to avoid copying Atoms held inside
- Moved numbers into std and the shared parser into base
- Started implementation of Commands

orchid-api/src/proto.rs

@@ -82,7 +82,7 @@ pub enum ExtHostReq {
 #[extendable]
 pub enum ExtHostNotif {
   ExprNotif(expr::ExprNotif),
-  ErrNotif(error::ErrNotif),
+  AdviseSweep(interner::AdviseSweep),
 }
 
 pub struct ExtHostChannel;
@@ -100,7 +100,7 @@ pub enum HostExtReq {
   Sweep(interner::Sweep),
   AtomReq(atom::AtomReq),
   ParserReq(parser::ParserReq),
-  GetConstTree(tree::GetConstTree),
+  GetMember(tree::GetMember),
   VfsReq(vfs::VfsReq),
 }