Multiple Proposed changes

Kind of difficult sending these changes seperately, so here's a big pull request.

 - Add the ability to start as a service and command line option to specify working directory

 example of creating service: 
    `sc create MMBotService binPath= "D:\Choco\\lib\mmbot.0.9.2\tools\mmbot\mmbot.exe -d D:\MMBotData"`
 - Add HtmlAgilityPack and GetHtml method under `HttpWraper` to mirror hubot html parsing
 - Add exchange rate script (needs htmlagilitypack) 
 - Add def programming script (needs htmlagilitypack)
 - Add the ability to change the default robot name that MMBot responds to via the MMBot.ini file 
    key: MMBOT_DEFAULT_NAME

Ignore the powershell and log4net commits, those changes were removed.