implement zdf indexer
add utility function to create string readFns
add generic testing for index functions
remove unused testing files
test Local function
improve tests for local function
test local sync function
implement sync with depth first algorithm
fix sync test
Add Path attribute to file struct
refactoring and cleanup of File struct
fix error logging
fix append method
remove the need for an adapter
move File into a seperate file
hopefully fixing travis build errors
add default http indexer
cleanup registry
test http package
improve http tests