added multithread support to important cpp functions
allowed to have secondary and tertary channels without seg plugins
error handling for browser: mouse recovers after error
Merge branch '1.4.x' of github.com:CellCognition/cecog into 1.4.x
reintroduced a high recursion depth maximum limit. Needed for the _forward_visitor
fixed #103
fixed error correction
Merge branch '1.4.x' of github.com:CellCognition/cecog into 1.4.x
merged from 1.4.x