Location of our Puppet modules has changed now that they are split
from system-config, update documentation accordingly.
Change-Id: I4d4adc5d41f50dd92fbd642ac30f95c327a416b2
Update the documentation for the Asterisk server. List the relevant
puppet bits, as well as where to find more documentation (the wiki for
user docs on calling in, and the free to read Asterisk book).
Change-Id: I91e97f5230868fe20c6432c046634b605d78b52c