Improved `mod_rewrite` check

see https://github.com/open-classifieds/openclassifieds2/issues/845#issuecomment-49769990 

added extra tests & refacto
Improved `mod_rewrite` check

see https://github.com/open-classifieds/openclassifieds2/issues/845#issuecomment-49769990

Added extra tests + refacto
[INSTALL] avoid error when unknown DB is specified
Update messages.po
Merge pull request #846 from emanwebdev/master

[INSTALL] Improved `mod_rewrite` check
improved install mod reqrite
[i18n] [oc-panel] settings/email.php
Merge pull request #848 from emanwebdev/master

[i18n] [oc-panel] settings/email.php
[i18n] [oc-panel] settings/general.php

Added i18n support for list/select of moderation types
Fix Alert message type: SUCCESS => ERROR
Merge pull request #849 from emanwebdev/master

[i18n] [oc-panel] settings/general.php