gnumake4 writerfilter gbuildization base

* this the base for writerfilter gbuildization from cws gnumake4
* this is the state of master that the gnumake4 gbuildization was done against
* all other changes from gnumake4 will directly be merged into master, only
  writerfilter will left out as it saw too much action on master
* To show the diff between the gbuildization in master and in gnumake4 run:
  git diff feature/gnumake4_writerfilter_base..feature/gnumake4_writerfilter_head
* this is a temprary tag and should be deleted once we have decided what to do
  with writerfilter