A better resolution to a possible circular dependency.

A better resolution to a possible circular dependency.

The runfolder subdirectory processing tools (firecrest, bustard, gerald, etc.)
were importing runfolder for some common constants, however runfolder
imported them to actually build the runfolder structure.

My previous solution was to only include the imports for the
sub-directory processing in the function that used them.
However that lead to needing nested functions which seemed confusing.

What I did was move the common constants into pipelines.__init__
and just imported them from there.