Adds String prisms for primitives.
Adds spec for String prisms. Strange Counter examples.
Abstracts constructing prisms for exception raising conversions.
Merge remote-tracking branch 'upstream/master'
Migrate StringExample to be a Spec.
Added lens for the last elements of the list
Fixed spelling mistake
Changed to init
Merge pull request #43 from rossh/42-lens-for-last-element-of-list

#42 lens for last element of list
#40 Add generalise head
#40 Add generalise last
#31 Add left/right most node lens for Tree
#31 Add rootLabe and subForest Lens for Tree
Add String instances for head and tail
#40 transform head and tail to Traversal and add Reverse
#30 - Add Tail
Catch up with master
Add reverse for Tree
#41 Add Init
Fix wrong trait case.