Update version and date for 3.13.

wiki/src/inc/stable_amd64_date.html

-2019-02-13
\ No newline at end of file
+2019-03-19
\ No newline at end of file

wiki/src/inc/stable_amd64_img_gpg_verify.html

-TZ=UTC gpg --no-options --keyid-format long --verify tails-amd64-3.12.1.img.sig tails-amd64-3.12.1.img
+TZ=UTC gpg --no-options --keyid-format long --verify tails-amd64-3.13.img.sig tails-amd64-3.13.img

wiki/src/inc/stable_amd64_img_sig_url.html

-https://tails.boum.org/torrents/files/tails-amd64-3.12.1.img.sig
+https://tails.boum.org/torrents/files/tails-amd64-3.13.img.sig

wiki/src/inc/stable_amd64_img_torrent_url.html

-https://tails.boum.org/torrents/files/tails-amd64-3.12.1.img.torrent
+https://tails.boum.org/torrents/files/tails-amd64-3.13.img.torrent

wiki/src/inc/stable_amd64_img_url.html

-http://dl.amnesia.boum.org/tails/stable/tails-amd64-3.12.1/tails-amd64-3.12.1.img
+http://dl.amnesia.boum.org/tails/stable/tails-amd64-3.13/tails-amd64-3.13.img

wiki/src/inc/stable_amd64_iso_gpg_verify.html

-TZ=UTC gpg --no-options --keyid-format long --verify tails-amd64-3.12.1.iso.sig tails-amd64-3.12.1.iso
+TZ=UTC gpg --no-options --keyid-format long --verify tails-amd64-3.13.iso.sig tails-amd64-3.13.iso

wiki/src/inc/stable_amd64_iso_sig_url.html

-https://tails.boum.org/torrents/files/tails-amd64-3.12.1.iso.sig
+https://tails.boum.org/torrents/files/tails-amd64-3.13.iso.sig

wiki/src/inc/stable_amd64_iso_torrent_url.html

-https://tails.boum.org/torrents/files/tails-amd64-3.12.1.iso.torrent
+https://tails.boum.org/torrents/files/tails-amd64-3.13.iso.torrent

wiki/src/inc/stable_amd64_iso_url.html

-http://dl.amnesia.boum.org/tails/stable/tails-amd64-3.12.1/tails-amd64-3.12.1.iso
+http://dl.amnesia.boum.org/tails/stable/tails-amd64-3.13/tails-amd64-3.13.iso

wiki/src/inc/stable_amd64_version.html

-3.12.1
+3.13