* `Generator` now supports `countof`

* initial support for threadlocal. doesn't work for ORC yet.

* `test_object`: demonstrating how to procedurally initialize a big global constant

* added support for ln operator

* `fold` supports shorthand `(x y z)` in place of `(x y z = x y z)`

* `loop` supports `(x y z)` shorthand for `(x y z = x y z)`

* fixed `assert` and `static-assert` computing their error messages unconditionally

* `Array`: added `'predicated-sort` function which allows to change the comparison function

* added `'serialize` method for lists

* fixed tuple comparisons

* fixed copy test
* implemented ordered comparisons for tuples

* Array: added comparison operator

* added `copy` support for `Array`, `testing.One` and `String`

* simplified feature matrix test

* enum test: test for procedural tag

* `Array`: forward generator can be explicitly created using `'forward`, takes optional offset argument
* `Array`: reverse generator takes optional offset argument

* fixed wording in error message

* removed unimplemented builtins from identifiers

* `String`: fixed numerous problems where the string would no longer be zero terminated after edits

* Fixed `emplace-append-many` for `String` and `Array` using the wrong offset. (tests by Westerbly Snaydley)