create visual studio extension

@dbolkensteyn 

create a small extension for you to try in visual studio... fix some issues about initialization of some parameters. on top of this ive integrated the analyser also with the visual studio extension.  See https://github.com/jmecosta/VSSonarQubeExtension/tree/vs2015-roslyn. The extension looks like it has a few issues because of the porting... but mostly it works... i will fix those soon.

Now the main issue here, seems this https://roslyn.codeplex.com/discussions/572015. Currently rosylin does not provide a way to modify, configure rules on the fly (disable is the one am after), so that we can get the quality profile from server and enable only the correct rules (same for any needed parameter). 

For the  VSSonarQubeExtension side we have all this information available. So for the time being one thing that could be done is that the sonar extension at startup would write a json configuration file with all the needed information (enable status, parameters), that could be use at runtime by the rule to access if can run or not.  If you are happy with this, i can prototype something on my side to show you.