Documentation: another update to reserved names list
Added missing user functions.
Also fixed a typo in common_functions.rst.
diff --git a/user_guide_src/source/general/common_functions.rst b/user_guide_src/source/general/common_functions.rst
index 7917d32..79bd9b4 100644
--- a/user_guide_src/source/general/common_functions.rst
+++ b/user_guide_src/source/general/common_functions.rst
@@ -31,7 +31,7 @@
is_really_writable()
====================
-.. php:function:: is_really_writeable($file)
+.. php:function:: is_really_writable($file)
:param string $file: File path
:returns: bool