- add batch file to setup the msys2 included with OpenModelica installation

- add readme about the setup

git-svn-id: https://openmodelica.org/svn/OpenModelicaExternal/trunk/tools/windows/OMDev@200 20e99eb2-9666-4e79-a4bd-0251279e2d9b

tools/MSYS_SETUP.bat

+@echo off
+
+if %OPENMODELICAHOME%a==a (goto :OPENMODELICAHOME_NOTOK) else (goto :OPENMODELICAHOME_OK)
+
+:OPENMODELICAHOME_NOTOK
+echo OPENMODELICAHOME environment variable not defined! Please define it!
+pause
+exit 1
+
+:OPENMODELICAHOME_OK
+REM generate passwd and group
+echo Generate %OPENMODELICAHOME%/tools/msys/etc/passwd and %OPENMODELICAHOME%/tools/msys/etc/group
+%OPENMODELICAHOME%/tools/msys/usr/bin/mkpasswd -l -c > %OPENMODELICAHOME%//tools/msys/etc/passwd
+%OPENMODELICAHOME%/tools/msys/usr/bin/mkgroup -l -c > %OPENMODELICAHOME%//tools/msys/etc/group

tools/MSYS_SETUP.txt

+OpenModelica Included Development Environment-MSYS2+MINGW32/MINGW64
+-------------------------------------------------------------------
+Adrian.Pop@liu.se, 2010-10-24, last update: 2017-03-10
+-------------------------------------------------------------------
+
+WARNING NOTE:
+- DO NOT DO THIS IF YOU HAVE OMDev installed!
+- this file explains how to setup the msys included in the OpenModelica installation
+
+To check for an updated version of this package go to:
+https://openmodelica.org/svn/OpenModelicaExternal/trunk/tools/windows/OMDev/tools
+
+VERY IMPORTANT INSTALLATION ISSUES!
+***********************************
+
+MSYS setting
+============
+To make things move fast in msys2 one has to generate the group and passwd files on the host.
+Open windows command prompt (cmd) and run %OPENMODELICAHOME%\tools\MSYS_SETUP.bat file.
+
+MINGW32 or MINGW64
+==================
+To build using 32 bit GCC you run:
+%OPENMODELICAHOME%\tools\msys\mingw32_shell.bat
+To build using 64 bit GCC you run:
+%OPENMODELICAHOME%\tools\msys\mingw64_shell.bat
+
+ENVIRONMENT VARIABLE SETTINGS
+=============================
+- note that msys_shell.bat mingw32_shell.bat mingw64_shell.bat
+  + do not use Windows PATH varible. If you want to use the 
+    Windows path variable define an environment varible called
+    MSYS2_PATH_TYPE=inherit
+	or you can call the batch scripts with -use-full-path
+  + do not use Windows TEMP directory but the directory:
+    %OPENMODELICAHOME%\tools\msys\tmp
+	if you want to change this behavior edit:
+	%OPENMODELICAHOME%\tools\msys\etc\profile
+	or define $TEMP and $TMP in the terminal
+- if you want to use the msys shell from Windows command line
+  make sure you set MSYSTEM to one of MSYS, MINGW32, MINGW64
+  if you do:
+  set MSYSTEM=MINGW32 you get the 32 bit GCC (mingw32_shell.bat)
+  set MSYSTEM=MINGW64 you get the 64 bit GCC (mingw64_shell.bat)
+  set MSYSTEM=MSYS use for updating MSYS     (msys2_shell.bat)
+
+Address questions/problems to:
+Adrian Pop,
+Adrian.Pop@liu.se