TDAQ Finding Updates, master branch (2019.01.24.)

Updated the PostConfig files of the projects to set up tdaq releases correctly...

After the update in the naming convention for the variables specifying where to pick up tdaq releases from (!20525 (merged)), I forgot to update the PostConfig.cmake files generated by the releases to use this same convention. ☹ This is fixing that.

At the same time I made the variables into cache variables, so it would be easier to override these defaults while building a project (like WorkDir) on top of a release.

@ssnyder, @tsulaia, this is the MR which should fix the issue with the nightly...