package/prosody: new package

package/prosody: new package

As stated by the upstream developers, Prosody only supports
lua-5.1 or luajit (which is a lua-5.1 interpreter):

> Response from zash at zash.se:
>
>> I pegged the package to lua 5,1 based on the contents of the
>> INSTALL file. Is this a hard requirement?
>
> Up until Prosody 0.9 Lua 5.1 is required. However LuaJIT
> implements Lua 5.1 so it works.

The license terms are not very consistent: the source files all
state to be "MIT/X11 licensed" and defer to the COPYING file for
details, but that file only has the text for the MIT license.
Thus, we believe the license to be MIT/X11, as stated in the source
files.

This installs the base system with certificates for two domains:
localhost and example.com

The default runtime configuration is tweaked during installation
to properly setup logging and pid-file directories.

Prosody doesn't like being executed as root, and thus the daemon
is executed as the user prosody. The startup script creates the
pid file write location with appropriate permissions.

Signed-off-by: Dushara Jayasinghe <nidujay@gmail.com>
Reviewed-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>