Most files suffered major changes

- Less ambiguous syntax
- Better parser (Chumsky only does tokenization now)
- Tidy(|ier) error handling
- Facade for simplified embedding
- External code grouped in (fairly) self-contained Systems
- Dynamic action dispatch
- Many STL additions

src/utils/mod.rs

@@ -1,4 +1,7 @@
 mod cache;
+mod delete_cell;
+mod event_poller;
+mod iter_find;
 mod print_nname;
 mod pushed;
 mod rc_to_owned;
@@ -7,8 +10,9 @@ mod side;
 mod split_max_prefix;
 mod string_from_charset;
 mod substack;
+mod take_with_output;
+mod thread_pool;
 mod unwrap_or;
-mod iter_find;
 
 pub use cache::Cache;
 pub use print_nname::sym2string;
@@ -20,6 +24,10 @@ pub use split_max_prefix::split_max_prefix;
 pub use substack::{Stackframe, Substack, SubstackIterator};
 pub(crate) use unwrap_or::unwrap_or;
 pub mod iter;
+pub use delete_cell::DeleteCell;
+pub use event_poller::{PollEvent, Poller};
 pub use iter::BoxedIter;
-pub use string_from_charset::string_from_charset;
 pub use iter_find::iter_find;
+pub use string_from_charset::string_from_charset;
+pub use take_with_output::take_with_output;
+pub use thread_pool::{Query, QueryTask, Task, ThreadPool};