turn ircecho into a parameterized class

in I6e5d832c9 I moved the variables for
it out of the node level, so they are not set
in site.pp anymore but instead in a role class.

this was to make it a role that beta can apply
on labs

but as Alex pointed out there it introduced
a regression for puppet3 compat. as suggested,
turn ircecho into a parameterized class instead

Change-Id: Ic3bd7c82635dfd1c4c85ee18827f089527a87975
Merge "turn ircecho into a parameterized class" into production