Simplify parameter validation in fragment.pp

This removes the use of resource defaults and just passes undef values
instead when we want to use the default parameter values on the file
resource for the fragment file.
Separate file resources from each other

Separate the different file resources from each other to make the source
more clear.
Remove 0.24.x compatibility code

Simplify the code by removing all the cruft needed for 0.24.x
compatibility, everyone should be using a newer puppet version by now.
Format correctly concat::fragment declaration
Add an ensure parameter to concat define
This parameter controls whether ressources associated to concat
should be present or absent.
Update CHANGELOG
Remove trailing spaces
Fix breakage in concat::fragment

In concat::fragment, exec notify should not be removed so that
target file is rebuild whenever a fragment is removed (by setting
$ensure to absent).

In concat, add a "no op" exec using /bin/true (/usr/bin/true on
some system) so that dependencies are satisfied even when $ensure
is set to absent in concat.
Merge Dalen's changes

Simplify parameter validation in fragment.pp    6248206
Separate file resources from each other         738d3b0
Remove 0.24.x compatibility code                331fd39

Conflicts:
	CHANGELOG
	README.markdown
	manifests/fragment.pp
	manifests/init.pp
	manifests/setup.pp
Merge changes from FredericLespez

Format correctly concat::fragment declaration   337e09e
Add an ensure parameter to concat define        1c44ccf
Update CHANGELOG                                723c35c
Remove trailing spaces                          1e976a4
Fix breakage in concat::fragment                e145fd9

Conflicts:
	CHANGELOG
	manifests/fragment.pp
	manifests/init.pp