Update reference manpage and add $__type to code-local

To access the type library from `code-local`, it is required to have the
`$__type` variable. Else, the type-specific library can not be accessed.

cdist/core/code.py

@@ -196,6 +196,7 @@ class Code:
         env = os.environ.copy()
         env.update(self.env)
         env.update({
+            '__type': cdist_object.cdist_type.absolute_path,
             '__object': cdist_object.absolute_path,
             '__object_id': cdist_object.object_id,
         })

docs/src/cdist-reference.rst.sh

@@ -253,6 +253,11 @@ __global
     Directory that contains generic output like explorer.
 
     Available for: initial manifest, type manifest, type gencode, shell.
+__library
+    Directory that contains common code.
+
+    Available for: initial manifest, type manifest, type gencode, code scripts,
+      global explorer, type explorer.
 __messages_in
     File to read messages from.
 
@@ -301,11 +306,15 @@ __target_host_tags
 __type
     Path to the current type.
 
-    Available for: type manifest, type gencode.
+    Available for: type manifest, type gencode, local code.
 __type_explorer
     Directory that contains the type explorers.
 
     Available for: type explorer.
+__type_library
+    Directory that contains type-specific common code.
+
+    Available for: type explorer, code-remote.
 
 Environment variables (for writing)
 -----------------------------------