switch to type tags instead of objects (for now)
recognize a named node
refactor tokenize to parse char by char
make tokenizer recognize an edge name

Conflicts:
	spec/can_recognize_ascii_tree_tokens.cpp
recognize a horizontal edge
recognize an ascending edge part
recognize a descending edge part
recognize a vertical edge part
recognize three ascii_tree tokens in the same string
split test into two tests
test rename
allow spaces before and within a root node
allow spaces in a named node
use all named-chars in named-node test
recognize and edge-name surrounded by spaces
recognize the remaining tokens when surrounded by spaces
better assert message for test which compares vectors of tokens
extract assert logic and use it to simplify a similar test
recognize a root node next to a named node
simplify tests