Fix #52: Pass /debugAdapter arg directly to host

This change updates the debug adapter registration to remove the need for
the old .cmd hack to launch the PowerShell Editor Services host process
with the /debugAdapter flag.  VS Code 0.10.7 has been fixed so that
arguments in the debug adapter registration get passed through to the host
process.

Author: daviwil

package.json

@@ -113,7 +113,10 @@
                         "powershell"
                     ]
                 },
-                "program": "bin/PowerShellEditorServices.Host/bin/Debug/Microsoft.PowerShell.EditorServices.Host.DebugAdapter.cmd",
+                "program": "bin/Microsoft.PowerShell.EditorServices.Host.exe",
+                "args": [
+                    "/debugAdapter"
+                ],
                 "configurationAttributes": {
                     "launch": {
                         "required": [
@@ -143,7 +146,10 @@
                         "powershell"
                     ]
                 },
-                "program": "bin/Microsoft.PowerShell.EditorServices.Host.DebugAdapter.x86.cmd",
+                "program": "bin/Microsoft.PowerShell.EditorServices.Host.x86.exe",
+                "args": [
+                    "/debugAdapter"
+                ],
                 "configurationAttributes": {
                     "launch": {
                         "required": [