Refactors each TypeDispatcher to have its own separate collection
of types. Add isnan function which returns a boolean if that type
is present, otherwise returns the number 1 for true, and 0 for fase.
* Defines a BooleanT type
* adds options to the Type constructor, so far just to allow conversions
from other types
* renames Number type to NumberT
* records the name of types, and puts the name in the string representation
* defines a conversion fron BooleanT to NumberT, specified to be automatic
* stub code for automatic conversions, not yet complete
* BooleanT not yet added to nanomath
Checked that the new facilities do not disrupt the prior behavior on numbers.
