Fix custom import issues when using shell environments

Translator is enabled to exectue within other shell environments by
installing as a library (in addition to command line). As such, a
separate package "translator" is installed, and pulls in everything
under the translator/ directory.

Originally the design for custom classes was to allow users to specify
their own locations for custom classes that they define outside of the
translator code. In order for this to work in the shell environments,
the user would need to install these classes via a setup.py script.
For now this is too heavy of a requirement to place on the user, so
the design for this fix is that the user will need to manually copy
over their custom classes to the translator/custom directory.

We will revist the option to install custom classes via a user defined
setup.py at a later date.

Change-Id: Ib132d9fe768a954a226724929c074034cf898da3

translator/conf/translator.conf

@@ -1,4 +1,4 @@
 [DEFAULT]
 
 # Relative path location for custom types
-custom_types_location=contrib/hot
+custom_types_location=translator/custom/hot

translator/hot/translate_node_templates.py

@@ -66,6 +66,7 @@ def _generate_type_map():
 def _load_custom_mod(custom_path):
     '''Dynamically load the parent module for all the custom types.'''
 
+    fp = None
     try:
         fp, filename, desc = imp.find_module(custom_path)
         imp.load_module(custom_path.replace('/', '.'),
@@ -81,8 +82,12 @@ def _load_classes(locations, classes):
     '''Dynamically load all the classes from the given locations.'''
 
     for cls_path in locations:
+        # Use the absolute path of the class path
+        abs_path = os.path.dirname(os.path.abspath(__file__))
+        abs_path = abs_path.replace('translator/hot', cls_path)
+
         # Grab all the tosca type module files in the given path
-        mod_files = [f for f in os.listdir(cls_path) if f.endswith('.py')
+        mod_files = [f for f in os.listdir(abs_path) if f.endswith('.py')
                      and not f.startswith('__init__')
                      and f.startswith('tosca_')]