New packages: 'math' and 'time'

--HG--
rename : src/org/pitaya/util/Fraction.java => src/org/pitaya/math/Fraction.java
rename : src/org/pitaya/util/Numbers.java => src/org/pitaya/math/Numbers.java
rename : src/org/pitaya/util/RomanNumbers.java => src/org/pitaya/math/RomanNumbers.java
rename : src/org/pitaya/util/Chronometer.java => src/org/pitaya/time/Chronometer.java
rename : src/org/pitaya/util/Dates.java => src/org/pitaya/time/Dates.java
rename : src/org/pitaya/util/Duration.java => src/org/pitaya/time/Duration.java
rename : test/org/pitaya/util/FractionTest.java => test/org/pitaya/math/FractionTest.java
rename : test/org/pitaya/util/NumbersTest.java => test/org/pitaya/math/NumbersTest.java
rename : test/org/pitaya/util/RomanNumbersTest.java => test/org/pitaya/math/RomanNumbersTest.java
rename : test/org/pitaya/util/ChronometerTest.java => test/org/pitaya/time/ChronometerTest.java
rename : test/org/pitaya/util/DatesTest.java => test/org/pitaya/time/DatesTest.java
rename : test/org/pitaya/util/DurationTest.java => test/org/pitaya/time/DurationTest.java