Add adix/oats new-style Concept prototype & examples

Actual source files have more details, as always, but basically add adix/oats.nim: A new-style Concept backend prototype for open-addressed tables. It is nowhere near as thorough as adix/lptabz at this stage.

So util/lfreq.nim and now no longer needs a user to magically know how big the string data area will need to be, making it actually a pretty general purpose utility (which is good since the README refers to it in comparison with the bu/oft wrapper around the adix/amoft.AMOft sketch).

Also add some less generally useful test/comparison files related to adix/oats for the curious:

• tests/lfreq.awk: Like above written as a pure AWK 1-liner
• tests/wu.nim: Unique w/no counts allows smallest CPU cache footprint
• tests/wfr.nim: Fully bundled Knuth-McIlroy vocab analyzer (almost surely "overbundled" but big among CFRO guys).
• tests/kmCmp.sh: Knuth-McIlroy Problem comparisons of above

Make building nsort more portable

Work on making compiling SIMD-optimized cumsum & nsort more robust on x86_64 platforms.

This robustness is only compile-time CPU feature detection-oriented (run-time would seem to require either a non-intrinsics approach to assembly or separate C compilation units.). So, it matters if your nim.cfg/build flags have march=native (or whatnot) in them which is kind of a choice outside the package as it relates to binary compatibility/deployment.

Mostly just update cligen version dep.

This kind of "release noise" should now become rare with the new bu/nrel -u feature.

Stop using LineTooLong

Adapt to
nim-lang/Nim@3a08e2e

Fix bug when using older Nim compilers

See the only commit.

Fix nimble install when a dependency

That's it. Again thanks to @Gruruya .

Rename adix/stat -> mvstat; Fix nimble install

Big thing is stat -> mvstat rename; Right now the old name is still available but deprecated. Will probably be removed in 0.6.0.

Fix nimble install by moving cstats -> bu. Thanks to @Gruruya for pointing out the problem in #5 .

Updates, add tdigest, uniqce sketches

In more detail:

• Add merge API to lghisto
• Add tdigest tail quantile sketch.
• Add cardinality estimation sketch uniqce.nim
• Improve doc generation/re-do README to point to it.
• Rename adix/stat -> adix/mvstat

Even more in git log -p, of course.

B-tree & lfreq adjustments, slimSystem, add adix/amoft

Various B-tree fix-ups to make some things discardable/marked used/etc.

Allow user to boost util/lfreq data space, though it should be replaced by a less hokey thing when concepts work better..

Add new Count-Min Sketch-based adix/amoft.nim module for approximately k-most often problems, where right now k is not too large (probably need to tie into B-tree for large k and dynamically switch over for large k since the heap-scan-table is probably faster for k < 2000 which is likely the common case).

3 changes

Just:

• Get LPTabz.mmap compiling (but not quite working) under arc again. Works under refc, though.
• Track cligen findPathPattern for tests/anaPrime
• Add --uniq to util/lfreq