resurrect dtkWidgets and dtkCreator; fix compilation of dtkComposer layer
dtkCreator & dtkComposer compilation fixes
bring back composite node + fix warning  about mpi and node world
remove debug messages
add dtkFileIsBinary helper function
add implementations method in node factory + add back 'inv' node
partial manual merge of 1.5 year of commits of the master branch
fix missing nodes
fix export rules + other minor fixes
fix export rules
indent
handle node Remote
qt5: fix nodeAt (must use descending order)
handle old composition for loop ports with kind = variant ( == proxyloop in new format)
Merge branch 'composer'