FIX #130 Chaotic mouse rollover painting on JTable (java8)

compareTo should follow the contract
sgn(x.compareTo(y)) == -sgn(y.compareTo(x))

fix TableCellId hashCode (it was equal 0 for all values)
code style: restore original formatting
java 1.6 compatibility

remove call of Integer.compareTo(int,int) method (since java 1.7)
Merge pull request #131 from Apri1/master

FIX #130 Chaotic mouse rollover painting on JTable (java8)