HACKING: fix some wording / changed macros / changed dirs.

HACKING

@@ -76,13 +76,14 @@ file. If you add a new directory you will need to create a new Modules.am,
 inside that directory. Do not forget to add a corresponding
 Makefile line at the end of configure.ac for this new Modules.am file.
 
-To have the module built, you need to add a call to VLC_ADD_PLUGINS or
+To have the module built, you need to add a call to VLC_ADD_PLUGIN or
 VLC_ADD_BUILTINS to configure.ac with your new module name as argument.
 Look at other modules for guidelines on how to add build and linkage options.
 
 After changing configure.ac you will always need to rerun bootstrap and 
 configure.
 
-VLC keeps a cache of its module (in ~/.vlc/cache on Linux), so you'll have to delete it. (or use vlc --reset-plugins-cache)
-Then use vlc -vvv --color --list to check that your plugin is seen by VLC.
+VLC keeps a cache of its modules (in ~/.cache/vlc/ on Linux), so you'll have to
+delete it (or use vlc --reset-plugins-cache). Then use vlc -vvv --color --list
+to check that your plugin is seen by VLC.