copy: Implement recursive copying if src is a directory.

If src param to copy is a directory, all files under it are collected
and pushed one by one to target. Source dir path handled in a way
simalar to rsync: if it ends with slash, only inside contents of
directory are copied to destination, otherwise the dir itself is
copied (with all contents of course). Original idea and implementation
by https://github.com/ansible/ansible/pull/1809 . Rewritten to address
review comments and simplify/correct logic.

files/copy

@@ -31,6 +31,10 @@ options:
   src:
     description:
       - Local path to a file to copy to the remote server; can be absolute or relative.
+        If path is a directory, it is copied recursively. In this case, if path ends
+        with "/", only inside contents of that directory are copied to destination.
+        Otherwise, if it does not end with "/", the directory itself with all contents
+        is copied. This behavior is similar to Rsync.
     required: false
     default: null
     aliases: []
@@ -42,7 +46,8 @@ options:
     default: null
   dest:
     description:
-      - Remote absolute path where the file should be copied to.
+      - Remote absolute path where the file should be copied to. If src is a directory,
+        this must be a directory too.
     required: true
     default: null
   backup:
@@ -76,8 +81,8 @@ options:
     required: false
 author: Michael DeHaan
 notes:
-   - The "copy" module can't be used to recursively copy directory structures to the target machine. Please see the
+   - The "copy" module recursively copy facility does not scale to lots (>hundreds) of files.
-     "Delegation" section of the Advanced Playbooks documentation for a better approach to recursive copies.
+     For alternative, see "Delegation" section of the Advanced Playbooks documentation.
 '''
 
 EXAMPLES = '''
@@ -122,6 +127,13 @@ def main():
     md5sum_src = module.md5(src)
     md5sum_dest = None
 
+    # Special handling for recursive copy - create intermediate dirs
+    if original_basename and dest.endswith("/"):
+        dest = os.path.join(dest, original_basename)
+        dirname = os.path.dirname(dest)
+        if not os.path.exists(dirname):
+            os.makedirs(dirname)
+
     if os.path.exists(dest):
         if not force:
             module.exit_json(msg="file already exists", src=src, dest=dest, changed=False)