Log Message:
Update chicken-current to 4.1.0

Changelog for 4.1.0:
- The new parameter "parantheses-synonyms" and the command-line
  option "-no-parantheses-synonyms" allows disabling list-like behaviour
  of "{ ... }" and "[ ... ]" tokens
- The new parameter "symbol-escape" and the command-line
  option "-no-symbol-escape" allows disabling "| ... |" \ 
symbol escape
  syntax
- Added command-line option "-r5rs-syntax" to disable CHICKEN-specific
  read-syntax
- Added compiler command-line-option "-no-compiler-syntax"
- Deprecated "getenv" (use "get-environment-variable" instead)
- Removed "macro?" and "undefine-macro!"
- Support for Microsoft Visual Studio / MSVC has been dropped
- The compiler provides now a simple flow-analysis pass that does
  basic checking of argument-count and -types for core library procedures
  (new option "-scrutinize")
- New compiler-options "-no-argc-checks", "-no-bound-checks",
  "-no-procedure checks", \ 
"-no-procedure-checks-for-usual-bindings",
  "-types TYPEFILE" and "-consult-inline-file FILENAME"
- Added a "chicken-setup" stub-application to catch incorrect use of
  this tool (which has been replaced in 4.0.0 with "chicken-install")
- Changed "setup-install-flag" and "setup-verbose-flag" to
  "setup-install-mode" and "setup-verbose-mode" in \ 
"setup-api" module,
  the old names are still available but deprecated
- Posix unit:
  added "socket?", "block-device?" and \ 
"character-device?", deprecated
  redundant "stat-..." procedures
- Also in Posix unit: "canonical-path" has been deprecated, \ 
"normalize-pathname"
  from the "files" unit provides now most of the functionality
- Added "directory-exists?"
- "(for-each (lambda ...) X)" is compiled as a loop
- The argument-count check for format-strings for "[sf]printf" with a \ 
constant 
  string argument is done at compile-time
- A stub application named "chicken-setup" is installed to catch when a 
  user invokes theobsolete tool instead of the new "chicken-install".