- added support of special characters in switch argument, fixed small typo in switched file naming

 This fix corrent issue when you have special characters in your switch value that could not be repesented as a file. ([swith][value].[mockFile])

```json
"webServers" : {
   "some/url" : {
      "mockFile" : "file.json",
      "verbs" : ["get"],
      "switch": "path"
   }
}
```

with following URI:

```url
http://somehost/some/url?path=/
```
will now try to search for "path2%F.file.json" instead of "path/.file.json"