README: typo
rename Decimal => Double

for consistency, to avoid further confusion.
Renamed to: PN_TDOUBLE, PNDouble, PN_IS_DOUBLE
bump ChangeLog
Rename potion_decimal to potion_double

but this is still inconsistent. potion_double should be the initializer, not
potion_real.
Rename potion_double to potion_strtod, potion_real to potion_double

potion_double is now the type initializer. Now we have almost consistent type names
Rename PN_IS_NUM to PN_IS_INT
PN_FNUMBER=>PN_FINTEGER, add seperate int+dbl methods

IS_NUM is a misnomer. Number is Integer or Double.
Provide seperate methods for future specialized _ii and _dd ops,
esp. with the upcoming type inferencer or typed variables
intdbl: initialize int+dbl vtables, add I+D sig types

int+dbl vtables derive now from number, not obj.
Still a couple of problems
Fix all tests: a literal int is still just a Number,

not an Integer. It is easier that way still. The type inferencer or
excplicity types will make them Integer then. Ditto for step, times, to.

Add a number? method.
PN_IS_DBL: also check for new vtable TDOUBLE (not yet used)
doc: explain the two-adress scheme

compared to a stack-based VM with no args, and a typcial three-address register
machine with possible SSA transformation for a static optimizable compiler
oo: add isa? and subclass? methods

Warning: subclass? just walks a single inheritence list yet,
This will miss some mixin combinations, multiple inheritance (e.g. perl @ISA)
Need to implement Packed Vector Encoding (http://www.eecs.berkeley.edu/~jrb/pve/)
re-enable test/classes/creature.pn
numbers: add type checks to all ops

mostly only with DEBUG
add PN_IS_NUM: int or dbl, bigint not yet
k&r brace style for greg
fix example/fannkuch.pn for #75 -1
Merge remote-tracking branch 'potion/master' into p2
Merge more potion type and method names