add tests
add contracts to converters, remove redundant checking, add contract predicates, change provide to exclude contract predicates from being provided, make hex-> case-insensitive but ->hex always return strings with downcase letters, make negative and fraction (non-whole-number) values impossible to give or receive for all functions
add trailing newline
add leading zero for ->hex results and make ->hex produce upcased strings
Merge branch 'Halfwake-master'