moved to using appdirs for sunpyrc config

changelog/2911.trivial.rst

@@ -0,0 +1 @@
+Moved to using `AppDirs <https://github.com/ActiveState/appdirs>`_ as the place to host our configuration file.

sunpy/data/sunpyrc

@@ -5,13 +5,12 @@
 ; of it on your system in site-packages/sunpy/data/sunpyrc.  If you edit it
 ; there, please note that it will be overridden in your next install.
 ; If you want to keep a permanent local copy that will not be
-; over-written, place it in HOME/.sunpy/sunpyrc (unix/linux
-; like systems) and C:\Documents and Settings\yourname\.sunpy
-; (win32 systems).
-;
+; over-written, we use AppDirs https://pypi.org/project/appdirs/
+; to find the right place for each OS to place it.
+; So if you open the link, you can find the user_config_dir
+; or print(sunpy.util.config.CONFIG_DIR) to find it on your own system.
 ; Note that any relative filepaths specified in the SunPy configuration file
 ; will be relative to SunPy's working directory.
-;
 
 ;;;;;;;;;;;;;;;;;;;
 ; General Options ;
@@ -51,6 +50,6 @@ sample_dir = data/sample_data
 ; Location to specify sunpy database parameters.
 ; The default url of the database location can specified here. The url of
 ; the database comprises the database driver, its location and name, as well
-; as optional authentication parameters 
+; as optional authentication parameters
 ; Default value: sqlite:////<user's home directory>/sunpy/sunpydb.sqlite
-; url = sqlite:////home/$USER/sunpy/sunpydb.sqlite
+; url = sqlite:////home/$USER/sunpy/sunpydb.sqlite

sunpy/extern/README.rst

@@ -0,0 +1,13 @@
+sunpy.extern
+============
+
+This sub-package contains third-party Python packages/modules that are
+required for some of SunPy's core functionality.
+
+In particular, this currently includes for Python:
+
+- `AppDirs`_ (Python 2 and 3 versions): This provides the core config file handling for SunPy's configuration system.
+
+To replace any of the other Python modules included in this package, simply remove them and update any imports in SunPy to import the system versions rather than the bundled copies.
+
+.. _AppDirs: https://github.com/ActiveState/appdirs