Check for extended_real rather than real in all the comparison routines in numbers.py
Fix typo

NegativeInfinity should be negative, not positive.
Set +/-oo to be comparable

This lets things evaluate them in comparisons.
Merge pull request #60 from smichr/olda

keep minimal definitions of number attributes
Merge branch 'old-assump' of github.com:asmeurer/sympy into old-assump

Conflicts:
	sympy/core/numbers.py
Expr._eval_is_negative and Expr._eval_is_positive check for extended_real instead of real
nan is neither infinite nor finite

This sets most facts about nan as False via automatic deduction.
Make Number.is_finite default to None

Not all Number subclasses are finite (Infinity and NegativeInfinity subclass
Number). Without this, we get strange errors unless we explicitly set
Infinity.is_finite and NegativeInfinity.is_finite to False.
put triggers first; don't tell unless you have the method

If the triggers are done first then it seems a routine
can be assured that none of the simple triggers are true.

The InconsistenAssumption error was being emitted when
we tried to tell something. Don't use tell unless you are
going to actually start the process. Hence, put it in the
else part of the `try`.