PySerial installation for Windows updated (#1)

HISTORY.md

@@ -9,6 +9,7 @@ I tried to give credit whenever possible. If I have missed anyone, kindly add it
 - Fix: Updated CXXFLAGS_STD to match upstream 1.6 (issue #424) (https://github.com/calvinli)
 - Fix: Added support for attiny core's use of chip instead of cpu in submenus (https://github.com/straccio)
 - Fix: ARDUINO_VERSION can cope with the longer 1.6.10 version string (issue #444) (https://github.com/sej7278)
+- Tweak: Documentation for Windows updated to include installation of PySerial (https://github.com/sovcik) 
 
 ### 1.5.1 (Debian version: 1.5-3) (2016-02-22)
 

README.md

@@ -122,8 +122,20 @@ sudo port install py27-serial
 
 On Windows:
 
-You need to install Cygwin and its packages for Make, Perl and the following Serial library
-or you can install it using the [pre-built package installer](https://pypi.python.org/pypi/pyserial)
+You need to install Cygwin and its packages for Make, Perl and the following Serial library.
+
+Assuming you included Python in your Cygwin installation:
+
+1. download PySerial source package from [https://pypi.python.org/pypi/pyserial](https://pypi.python.org/pypi/pyserial)
+2. extract downloaded package running
+```tar xvzf dowloaded_package_name.tar.gz```
+3. navigate to extracted package folder
+4. build and install Python module: 
+
+```
+python setup.py build
+python setup.py install
+```
 
 ## Usage