Squashed commit of the following:

commit 1345201c9da99a82f198e41fba24da6b0d7ae59a
Author: Björn Schießle <schiessle@owncloud.com>
Date:   Thu Jun 20 16:27:46 2013 +0200

    add l10n support

commit bf2c79c8de8710e839a4a55642a91874c374fa1c
Author: Björn Schießle <schiessle@owncloud.com>
Date:   Thu Jun 20 16:19:10 2013 +0200

    only init session if openssl extension is loaded

commit cbd52af6afbaa310bb1a534db64ff5e476dfd5d7
Author: Björn Schießle <schiessle@owncloud.com>
Date:   Thu Jun 20 12:25:40 2013 +0200

    first disable app and than show error page

commit 55baf593179c433642de59552592e6b0f1932880
Author: Björn Schießle <schiessle@owncloud.com>
Date:   Thu Jun 20 12:17:34 2013 +0200

    typo fixed

commit 1d9bef0b058e7cc3d511b81ae12d5a07660c75b2
Author: Björn Schießle <schiessle@owncloud.com>
Date:   Thu Jun 20 12:15:40 2013 +0200

    move dependency check to the encryption app

commit c186e95da526f0470e20f014f1bd9513db5518ff
Author: Björn Schießle <schiessle@owncloud.com>
Date:   Thu Jun 20 11:13:11 2013 +0200

    make sure that openssl is installed and loaded