Misc fixes

[skirpichev]

• adjust defaults for rnd: 'd' -> round_fast, 'f' -> round_floor
• make explicit rnd=round_fast for to_int()
• set defaults rnd=round_fast for mpf_bernoulli*
• clear unused imports in mpmath/libmp/*.py
• use prec=0 in libmp/*.py
• drop libmp.HASH_MODULUS
• drop libmp.HASH_BITS
• drop libmp.math_float_inf
• adjust nan's hashing for Python versions >= 3.10
• use to_man_exp() in mpf.man_exp to raise exceptions
• improve coverage
• add missing type cast in from_npfloat() and test
• add type-cast for mantissa in _mpf_ 4-tuple (mpf constructor)
• turn DeprecationWarning's into errors in CI
• fail test suite if xfail'ed test - pass
• support more number syntaxes, closes Support different number syntaxes #184