Support for whitespace for bootstrap/casper_path

Adding quotations around the file path to allow whitespace in the path
for the bootstrap.js file passed to the execution engine and the
CASPER_PATH argument.

@@ -149,8 +149,8 @@ class casperjs {
         var CASPER_COMMAND = new List<string>(ENGINE_EXEC);
         CASPER_COMMAND.AddRange(ENGINE_ARGS);
         CASPER_COMMAND.AddRange(new [] {
-            Path.Combine(Path.Combine(CASPER_PATH, "bin"), "bootstrap.js"),
-            "--casper-path=" + CASPER_PATH,
+            @"""" + Path.Combine(CASPER_PATH, "bin\\bootstrap.js") + @"""",
+            @"--casper-path=""" + CASPER_PATH + @"""",
             "--cli"
         });
         CASPER_COMMAND.AddRange(CASPER_ARGS);