Remove incorrect _deprecated_function() calls.
Use add_query_arg() instead of url concatenation in wpsc_user_profile_links().
Avoid using unnecessary $i iterator in wpsc_user_profile_links().
Use include() to include "your account" templates rather than
include_once()
Appease @JustinSainton's nitpickiness by correcting the PHP comments
which should reflect hierarchical relationship between templates.
Whitespace fix
Refactor wpsc-account-downloads.php so that it contains less logic and
more template.

Also added HTML classes to the table rows, make sure the table has
<thead> and <tbody>.
Escape URL in wpsc-user-log.php.