Add warnings for deprecated assumptions bounded/unbounded

In [6]: x.is_unbounded
/home/sk/src/sympy/sympy/sympy/core/basic.py:1599: UserWarning: is_unbounded is deprecated: use is_infinite instead
  warnings.warn('is_unbounded is deprecated: use is_infinite instead')

In [7]: x.is_unbounded

In [8]: b = Symbol('b', bounded=True)
/home/sk/src/sympy/sympy/sympy/core/symbol.py:575: UserWarning: bounded assumption is deprecated, use finite instead
  warnings.warn('bounded assumption is deprecated, use finite instead')

In [9]: b.assumptions0
Out[9]: {'commutative': True, 'finite': True, 'infinite': False}

In [10]: b2 = Symbol('b2', bounded=True)

In [11]: