Merge pull request #292 from ruda/main_entry_point

 Run avocado when called by 'python -m avocado'

avocado/__main__.py

+"""
+Main entry point when called by 'python -m'.
+"""
+
+import sys
+
+from avocado.cli.app import AvocadoApp
+
+if sys.argv[0].endswith('__main__.py'):
+    sys.argv[0] = 'python -m avocado'
+
+main = AvocadoApp()
+main.run()