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.
Catch up with master
Adds number parsing prisms. #32 #33
Move trySimplePrism and add comment explaining non acii-digits behavior
Add more clarification about non-ascii digits
Merge pull request #46 from NightRa/StringPrisms

#32 safec ast String to Number