add testmail on general page

...delibs/fess/app/web/admin/general/AdminGeneralAction.java

...ava/org/codelibs/fess/app/web/admin/general/MailForm.java

src/main/java/org/codelibs/fess/exec/Crawler.java

...ain/java/org/codelibs/fess/mylasta/action/FessLabels.java

...n/java/org/codelibs/fess/mylasta/action/FessMessages.java

.../java/org/codelibs/fess/mylasta/direction/FessConfig.java

...java/org/codelibs/fess/mylasta/mail/TestmailPostcard.java

src/main/resources/fess_env_crawler.properties

src/main/resources/fess_env_suggest.properties

src/main/resources/fess_label.properties

src/main/resources/fess_label_en.properties

src/main/resources/fess_label_ja.properties

src/main/resources/fess_message.properties

src/main/resources/fess_message_en.properties

src/main/resources/fess_message_ja.properties

src/main/resources/mail/testmail.dfmail

src/main/webapp/WEB-INF/view/admin/general/admin_general.jsp