made the pack completely portable and wrote relevent bat files to go with it

gitportable/mingw64/lib/tcl8.6/tzdata/Asia/Dhaka

@@ -0,0 +1,13 @@
+# created by tools/tclZIC.tcl - do not edit
+
+set TZData(:Asia/Dhaka) {
+    {-9223372036854775808 21700 0 LMT}
+    {-2524543300 21200 0 HMT}
+    {-891582800 23400 0 +0630}
+    {-872058600 19800 0 +0530}
+    {-862637400 23400 0 +0630}
+    {-576138600 21600 0 +06}
+    {1230746400 21600 0 +06}
+    {1245430800 25200 1 +06}
+    {1262278800 21600 0 +06}
+}