develop/httpserver.rst: fix links & HTML5

All links to the plugins went to ProgVal/Limnoria, most of them are
really at ProgVal/Supybot-plugins.

Code examples now use HTML5.
use/getting_started.rst: replace pastebinit wit...

h curl

curl is more often installed than pastebinit and is widely used and
might be installed by default on some systems (I believe Fedora 20 is
one of these).
Merge pull request #16 from Mkaysi/httpserver

develop/httpserver.rst: fix links & HTML5
Merge pull request #17 from Mkaysi/gpg

use/getting_started.rst: replace pastebinit wit...