bitbake: hob/bitbake: create a template (a .bb file) from hob through bitbake

Modified generateNewImage function from cooker, in order to be used to
save a template in Hob.
Created a command to ensure that some dirs are created. The templates
(recipes) will be saved in {TOPDIR}/recipes/images folder.
Called these methods from Hob.

[YOCTO #4193]
(Bitbake rev: 96ffa00945c7eb09a0132fa47159aef3ef20fb3e)

Signed-off-by: Cristiana Voicu <cristiana.voicu@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/command.py

@@ -214,7 +214,13 @@ class CommandsSync:
         image = params[0]
         base_image = params[1]
         package_queue = params[2]
-        return command.cooker.generateNewImage(image, base_image, package_queue)
+        timestamp = params[3]
+        return command.cooker.generateNewImage(image, base_image,
+                                 package_queue, timestamp)
+
+    def ensureDir(self, command, params):
+        directory = params[0]
+        bb.utils.mkdirhier(directory)
 
     def setVarFile(self, command, params):
         """