* copy some prior art

* remove previous absl files

* renove abseil files

* add vendor in tools/

* it works!

* fix some initial check issues

* lazier config

* remove r 3.6 on windows

* see if removing the braces helps

* maybe fix substitution

* just link it all

* try again

* helppers

* slight updates

* better flags

* more cmake

* just hard code it

* pkg-config

* add gnu make to makefile

* don't link rt

* ignore windows dir

* possible progress for R 4.2

* more win checks

* don't use configure.win

* maybe working on R 4.2

* also use cxx17

* check for absl

* maybe with quotes

* version and news

* maybe the right flags

* maybe try unifying makevars

* maybe work on R 4.2/4/1

* maybe fix makevars.win

* maybe fix for R 4.2

* maybe fix R 4.1

* see if we're getting the right if statement

* temp fix for old s2 warnings

* maybe fix again

* try again

* document configure.win

* maybe fix R 4.2 warning

* try again for globals

* maybe use different namespace

* use pkg-config abseil

* fix comment

* maybe fix

* quality of life improvements

* clean news

* better cleanup/configure

* reasonable path to not awful dev setup without system abseil

* enforce minimum version in pkg-config check