MERGE: リビジョン1714のマージ。SQL文からバッククオート（`）を取り除いた。

MERGE: リビジョン1714のマージ。SQL文からバッククオート（`）を取り除いた。

http://nucleuscms.svn.sourceforge.net/viewvc/nucleuscms?view=revision&revision=1714

REMOVE: backtick (a.k.a backquote, grave accent) from identifier in SQL
statement

For enabling to use under several SQL implementations such as SQLite,
the sql statements generated by Nucleus CMS need to be compatible for
several SQL implements.

For this issue, we select ANSI SQL89 standard. According the standard,
identifier such as database name, table name and so on should consist of
alphanumeric and underscore with no quotations. ANSI SQL92 just allow us
to use reserved woords (a.k.a keywords) for identifier with double
quotation.

The identifier with backticks is MySQL extension. In detail, please
refer to MySQL document.
http://dev.mysql.com/doc/refman/5.0/en/identifiers.html