add modbus slave support

add modbus slave support

components/connectivity/Modbus/3rdparty/freemodbus-v1.6/tools/README.txt

@@ -0,0 +1,18 @@
+
+The tools have not been  bundled  because  of  license  restrictions.   I  can
+recommend the following tools to test the modbus implementation:
+
+ - Modpoll Modbus<75> Polling Tool: A free command line based Modbus
+   master simulator and test utility.
+
+   available: http://www.focus-sw.com/fieldtalk/modpoll.html
+
+ - Modbus Poll master simulator: A Modbus master simulator with a 
+   excellent user interface. Support RTU and ASCII modes.
+
+   available: http://www.modbustools.com/modbus_poll.asp
+
+Simple  download  the  Modpoll  Polling  Tool  and  place  it  with  the  name
+'modpoll.exe' in this directory. 
+
+

components/connectivity/Modbus/3rdparty/freemodbus-v1.6/tools/indent.sh

@@ -0,0 +1,28 @@
+#!/bin/sh
+
+MYDIR="/cygdrive/c/GnuWin32/bin/"
+
+$MYDIR/indent.exe --version
+$MYDIR/indent.exe \
+    --declaration-indentation16 \
+    --procnames-start-lines \
+    --blank-lines-after-procedures \
+    --break-before-boolean-operator \
+    --braces-after-if-line \
+    --braces-after-struct-decl-line \
+    --brace-indent0 \
+    --case-indentation0 \
+    --no-space-after-function-call-names \
+    --no-space-after-for \
+    --no-space-after-if \
+    --no-space-after-while \
+    --no-space-after-casts \
+    --space-after-parentheses \
+    --dont-format-comments \
+    --indent-level4 \
+    --ignore-newlines \
+    --no-tabs \
+    --line-length120 \
+    $@
+   
+unix2dos $@

components/connectivity/Modbus/3rdparty/freemodbus-v1.6/tools/lint-arm.sh

@@ -0,0 +1,5 @@
+splint \
+    -I. -I../../modbus/include -I../../modbus/rtu -I../../modbus/ascii \
+    -Iport -Ilibrary/include \
+    -Ifreertos/include -Ifreertos/portable/GCC/ARM7_STR71X/ \
+    -DSTR71X_GCC=1 -nullpass +charint -booltype BOOL $@

components/connectivity/Modbus/3rdparty/freemodbus-v1.6/tools/lint-avr.sh

@@ -0,0 +1,4 @@
+splint \
+    -I. -I../../modbus/include -I../../modbus/rtu -I../../modbus/ascii \
+    -Iport -I/cygdrive/c/WinAVR/avr/include \
+    -nullpass +charint -booltype BOOL -D__AVR_ATmega168__=1 $@