Exercises 3.4 and 3.5
Better solution to Exc. 3.4
named pose in Exc. 3.4
make "happly" a parsing notation for "ap10"
Mike's solution with ap10 path_contr
Merge pull request #512 from marcbezem/master

Exercises 3.4 and 3.5
Merge pull request #516 from mikeshulman/happly

make "happly" a parsing notation for "ap10"