Adding @defgroup and @ingroup doxygen tags into all headers
in the common folder that contain doxygen blocks.
This improves the structure, readability, and findability
of information in the resulting output.
This commit targets purely structure and does not deal with
the content of the currently existing doxygen documentation.
This removes the dependency on array.h from str.h.
Also, begun migration from the confusing type name "StringList" to
the more appropriate StringArray.
svn-id: r48282
