Dump config file

Add functionality to dump config file when calling a ConfigCommand

Fixes #61 (closed)

bob/extension/data/test_dump_config2.py

+'''Configuration file automatically generated at 08/07/2018
+cli test
+
+Blablabla bli blo
+
+Parameters
+----------
+xxx : :any:`list`
+    blabla blablo
+yyy : callable
+    bli bla blo bla bla bla
+
+[CONFIG]...           BLA BLA BLA BLA'''
+
+# database = None
+'''Required parameter: database (--database, -d)
+bla bla bla Can be a ``bob.extension.test_config_load`` entry point, a module name, or a path to a Python file which contains a variable named `database`.
+Registered entries are: ['basic_config', 'resource_config', 'subpackage_config']'''
+
+# annotator = None
+'''Required parameter: annotator (--annotator, -a)
+bli bli bli Can be a ``bob.extension.test_config_load`` entry point, a module name, or a path to a Python file which contains a variable named `annotator`.
+Registered entries are: ['basic_config', 'resource_config', 'subpackage_config']'''
+
+# output_dir = None
+'''Required parameter: output_dir (--output-dir, -o)
+blo blo blo'''
+
+# force = False
+'''Optional parameter: force (--force, -f) [default: False]
+lalalalalala'''
+
+# array = 1
+'''Optional parameter: array (--array) [default: 1]
+lililili'''
+
+# database_directories_file = ~/databases.txt
+'''Optional parameter: database_directories_file (--database-directories-file) [default: ~/databases.txt]
+lklklklk'''
+
+# verbose = 0
+'''Optional parameter: verbose (-v, --verbose) [default: 0]
+Increase the verbosity level from 0 (only error messages) to 1 (warnings), 2 (log messages), 3 (debug information) by adding the --verbose option as often as desired (e.g. '-vvv' for debug).'''