cache: move capacity into the Config

stree: a better definition of Find

stree: add a Find method

This is similar to Cursor, but selects the first key greater than or equal to
the given key rather than failing when the exact key is not found.

mstr: parameterize Trunc on string or []byte

Release v0.22.0

Maintenance:
- slice: use comparisons without subtraction
- godeps: add a tool dependency anchor

Breaking changes:
- slice: remove the Split function

Additions:
- mstr: add Split function

Release v0.21.4

- compare: add Bool comparison
- mapset: add Range constructor

Release v0.21.3

- Update examples and documentation
- mds: remove the oset package
- slice: add Select

stree: make Inorder and InorderAfter into range functions

These were very nearly range functions already, except that they returned a
Boolean result. Remove that result and rework the type signature of
InorderAfter to move the yield function into the iterator.

Update the usage in omap and oset.

Release v0.21.1

Changes:
- cache: remove the onSize argument from Evict
- shell: convert the Each method into a range function

Maintenance:
- shell: add benchmarks for Join as well as Quote

Performance:
- shell: pool buffers and avoid reallocations in Quote and Join

all: change the signature of Each to be a range function (#20)

Most of the collections defined here already have an Each method that iterates
the contents of the collection and was almost compatible with the new range
function interface added in Go 1.23.

Here, we make it fully compatible, by discarding the Boolean return value from
the Each method itself. This bumps the required Go version from 1.22 to 1.23.
Technically we could avoid that by not updating the usage within the package
itself, but as far as I am aware all the consumers of this package are using Go
1.23 already.