adding support for unit testing on windows systems
modified:   Readme.md
new file:   make.bat
modified:   test/integration/connection/test-unix-domain-socket.js
test-unix-domain-socket.js: test reverted to previous version, added if-clause in the beginning

Reverted the test to the previous behaviour and added an IF-Clause in the beginning that skips the test if ```windir``` is set.
Update Readme.md

Using latest version the commit dd04dc10258c7333833582a8d11411bd65e51d37 by marcuswestin
Clarified the use of config option 'charset'

* `charset`: The charset for the connection. (Default: `'UTF8_GENERAL_CI'`. Value needs to be all in upper case letters!)
Merge pull request #496 from kai-koch/master

* Adding support for unit tests on windows systems
* Clarified the use of config option 'charset'