removed unused jpcleaners
* impled getRange with direct pointer to python sequence, uses direct cast instead of convertToJava methods.
* removed unused jpcleaners
add method setRange() with direct pointer to python seq
add method setArrayRange
impl setArraySlice with distinction for primitive types
added error checking via python internal casting routine and exception handling
added bounds check
added conversion failure test case
avoid crash if an empty slice is given
Merge pull request #54 from marscher/primitive_setter_improvment

Primitive array setter improvement, which avoids conversion of every element to a HostRef wrapper.

Error checking is performed in the actual implementation of the setRange function in primitive type classes via Python C-API - this is optimistic, but avoids an additional function call pair for every element (canConvertToJava and convertToJava). So memory is allocated/freed even when we conversion will fail. But considering large arrays this is really important.