replacing tailrec primitive syntax with simpler Prim.loop function

numeric literals are now case insensitive

italics

started fort standard library in lib

added colorize.fort example
now removing previously matched tags in sum alt default value

 include derivation trace in type checker errors

do exhaustiveness checking on case expressions

fixed where clause bug

refactored into custom AST
updated changelog and version

version 0.1.0.0 source