Improve rounded

[otaviojava]

Create new strategies to do rounding in monetary amount using:

• Scale, the number of digits to the right of the decimal point
• Precision, the total number of digits in a number
• both the resources

MonetaryOperator monetaryOperator = ScaleRoundedOperator.of(scale, RoundingMode.HALF_EVEN);
CurrencyUnit real = Monetary.getCurrency("BRL");
MonetaryAmount money = Money.of(BigDecimal.valueOf(35.34567), real);
MonetaryAmount result = monetaryOperator.apply(money); // BRL 35.3457

MathContext mathContext = new MathContext(4, RoundingMode.HALF_EVEN);
MonetaryOperator monetaryOperator = PrecisionContextRoundedOperator.of(mathContext);
CurrencyUnit real = Monetary.getCurrency("BRL");
MonetaryAmount money = Money.of(BigDecimal.valueOf(35.34567), real);
MonetaryAmount result = monetaryOperator.apply(money); // BRL 35.35

int scale = 3;
int precision = 5;
MathContext mathContext = new MathContext(precision, RoundingMode.HALF_EVEN);
MonetaryOperator monetaryOperator = PrecisionScaleRoundedOperator.of(scale, mathContext);
CurrencyUnit real = Monetary.getCurrency("BRL");
MonetaryAmount money = Money.of(BigDecimal.valueOf(35.34567), real);
MonetaryAmount result = monetaryOperator.apply(money); // BRL 35.346

Also MonetaryRoundedFactory, to make MonetaryAmount with rounding operator, informed previously:

MonetaryOperator monetaryOperator = MonetaryOperator.identity();
MonetaryRoundedFactory factory = MonetaryRoundedFactory.of(monetaryOperator);

MonetaryRoundedFactory factory = MonetaryRoundedFactory.of(MathContext.DECIMAL32);

int precision = 6;
RoundingMode roundingMode = RoundingMode.HALF_EVEN;
MonetaryRoundedFactory factory = MonetaryRoundedFactory
                .withRoundingMode(roundingMode).withPrecision(precision)
                .build();

int scale = 6;
RoundingMode roundingMode = RoundingMode.HALF_EVEN;
MonetaryRoundedFactory factory = MonetaryRoundedFactory
                .withRoundingMode(roundingMode).withScale(scale)
                .build();

int precision = 6;
int scale = 3;
RoundingMode roundingMode = RoundingMode.HALF_EVEN;
MonetaryRoundedFactory factory = MonetaryRoundedFactory
                .withRoundingMode(roundingMode).withPrecision(precision).withScale(scale)
                .build();

int precision = 6;
int scale = 3;
RoundingMode roundingMode = RoundingMode.HALF_EVEN;
MonetaryRoundedFactory factory = MonetaryRoundedFactory
                .withRoundingMode(roundingMode).withScale(scale).withPrecision(precision)
                .build();

MonetaryAmount monetaryAmount = factory.create(BigDecimal.TEN, real);

[coveralls]

Coverage increased (+0.31%) to 69.05% when pulling 5f82188 on round_factory into fe1dcba on master.

[coveralls]

Coverage increased (+0.31%) to 69.05% when pulling 5f82188 on round_factory into fe1dcba on master.