Update hold.pp

fix for default debian installations

all files in /etc/apt/preferences without _ will be silently ignore according to debian manpage. Addionally its not a good idea to write versionnumber in filename cause there is no way to delete this files if you increase versionumber

Update source_spec.rb

add a way to include debsrc only (useful for debian/ubuntu build server ... jenkins ect)

Update source_spec.rb

var rename

Update source.list.erb

add include_deb "switch"

Update source.pp

"include_deb" defaultvalue = true

Update hold_spec.rb

change the name of the preferences file (hold)

Update source_spec.rb

Update README.md

Doku: 'include_deb' included next to 'include_src' in examples

Update README.md

typo
Merge pull request #333 from wilman0/master

Fix for debian/ubuntu hold and a way to add debian src only
Cleaned up acceptance tests

A lot of the tests were testing things that really should be tested via
unit tests, so those were deleted and unit tests will be revamped to
make sure they are covering everything they need to be covering.
Cleaned up unit tests.