Jython support

Jython implements python 2.5, so there are two tweaks needed to be done.

* with statement is available in 2.6, but it's possible to get it from the future
* strings don't have format() method

Also, it's important to let jvm allocate enough memory

```
[dimazest@mac QSortTest]$ time jython -J-Xmx2G Qsort.py 7
Sorted 10000000 ints in python.

real	1m41.370s
user	2m14.970s
sys	0m1.769s
[dimazest@mac QSortTest]$ time jython -J-Xmx2G Qsort.py 6
Sorted 1000000 ints in python.

real	0m12.028s
user	0m16.018s
sys	0m0.455s
```