etr exit code, style errors, new bu/rs program

In etr unhandled exceptions were indistinguishable from the special input-output ratio exit code. Fixed this.

Fix a few identifier style errors.

Add a new reservoir sampler, bu/rs library|CLI utility.

Expand `fread` applicability & minor clean-ups

doc/fread.md has some more details with a worked fitl example.

Minor clean-ups are like std/ qualified imports and style-consistent idents.

Speed-up `topk` with new `adix/topk`; Make compile with gcc-14

Uses a new adix/topk to make bu/topn ϴ(lg k) faster and with output order options & a config file.

Make catz.nim and dirq.nim compile with gcc-14.

In particular, the dirq.nim exposes a Nim codegen problem where it is unclear how smooth a path forward exists Nim deprecation/back-compat-wise. For now just add a -Wno-error directive which works under gcc & clang.

Update docs, thermctl, catz & deps

Changes

• update docs variously
• hot summer days lead to making thermctl more reliable
• catz uses lz4c & -T0 for multi-threaded decompression
• update various nimble deps

Update to working fitl dep version

fitl/gof.nim was not compiling but part of fitl nimble install.

`tim` gets time units/more robust, `edplot` doc updates/refactor

The git log has more details, but besides a lot of improvement to edplot docs the headliner for this release is user-adjustable time units for tim (e.g. in your ~/.config/tim) via a string parameter -u=, --time-unit= which recognizes many well known time units that might be relevant. (Only up to "minutes" since you would not use tim for tests that individually take hours of real-time.)

Add edplot and --time-unit

One new program: edplot & documentation
(This induces direct dependency on spfun rather than prior
indirect via fitl dependency.)

Add a --time-unit/-u option for tim. Also update doc/tim.md
quite a bit finally adding the excellent blog post as footnote 1.

Also tweak etr formatting (but really it should probably
just take a format string template).

Updates to `tim` defaults & help

If anyone wouldn't just have their own ~/.config/tim files they get a less aggressively trying to be super accurate defaults that seem to work well for me (famous last words) with only fixed freq/chrt/taskset. Let those buyers pleased to only do 22 trials also beware, though! Also some doc & dependency updates.

Ok, ok.. Add all `catz` stuff to `bu` while we are at it.

And update the fitl dependency while at it (with the bump from overlooked uncommitted spfun/studentT API generalization).

A release just to update dependencies on newer adix & fitl releases.

That's it & that's all!