v0.6.2 - Retour en onefile, suppression _internal

Changements :
- Retour a --onefile : exe unique, plus besoin de _internal/
- Le fix Zone.Identifier (v0.5.9) resout le probleme de DLL pour les exe telecharges
- Suppression de _internal/ du repo et ajout au .gitignore
- build.bat simplifie

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

_internal/_tcl_data/msgs/nl.msg

@@ -1,50 +0,0 @@
-# created by tools/loadICU.tcl -- do not edit
-namespace eval ::tcl::clock {
-    ::msgcat::mcset nl DAYS_OF_WEEK_ABBREV [list \
-        "zo"\
-        "ma"\
-        "di"\
-        "wo"\
-        "do"\
-        "vr"\
-        "za"]
-    ::msgcat::mcset nl DAYS_OF_WEEK_FULL [list \
-        "zondag"\
-        "maandag"\
-        "dinsdag"\
-        "woensdag"\
-        "donderdag"\
-        "vrijdag"\
-        "zaterdag"]
-    ::msgcat::mcset nl MONTHS_ABBREV [list \
-        "jan"\
-        "feb"\
-        "mrt"\
-        "apr"\
-        "mei"\
-        "jun"\
-        "jul"\
-        "aug"\
-        "sep"\
-        "okt"\
-        "nov"\
-        "dec"\
-        ""]
-    ::msgcat::mcset nl MONTHS_FULL [list \
-        "januari"\
-        "februari"\
-        "maart"\
-        "april"\
-        "mei"\
-        "juni"\
-        "juli"\
-        "augustus"\
-        "september"\
-        "oktober"\
-        "november"\
-        "december"\
-        ""]
-    ::msgcat::mcset nl DATE_FORMAT "%e %B %Y"
-    ::msgcat::mcset nl TIME_FORMAT "%k:%M:%S"
-    ::msgcat::mcset nl DATE_TIME_FORMAT "%e %B %Y %k:%M:%S %z"
-}