detailed stracktrace only when option -d, second implemented in c++

Readme.md

@@ -69,18 +69,15 @@ utils/local_install.sh
 - multiline editing (see kilocpp editor)
 - execute system command should capture stderr
 - add some mem stats to benchmark
-- add tests for usql
 
 #### Code
 - add documentation
 - add more unit test, mainly for usql
 - rename constants in ml_profiler.h
-- replace to_string macro in ml.cpp
 - add instrumentation (time, nr of evals, num of atoms, debug info, debug environment etc)
 
 #### Language
 - support for "#t" or "t" symbol as a true and "#f" for false
-- support for exceptions
 - string functions
     - compare - needed for sorting, cmp ignore case
     - regexp match, regexp tokens    
@@ -91,8 +88,6 @@ utils/local_install.sh
   - get-env, set-env; set-env cannot be implemented in stdlib.lsp, because popen is in fact subshell
 
 #### Performance
-- define is one of most frequent callee, when in scope with very few vars, lookup sequentially
-- first, second are often called -> implement in c++
 - push_back - repeatedly without reserving size
 - range - with for(int i...) and reserving result size can be 3times faster on (range 1 10000)
 - mini_sprintf - unnecesary copying between vector and list