RFR(S): 7605373: Decrease count of CTW testlists

[Tatiana Pivovarova]

Hi all,

Please review this small enhancement.

bug-id: https://bugs.openjdk.java.net/browse/INTJDK-7605373
webrev: http://cr.openjdk.java.net/~tpivovarova/7605373/webrev.00/

Problem:
There are 106 testlist for ctw, so for 6 platforms, 4 tiered levels we 
have 2544 run jobs. Some of them have very small execution time (< 
1min), but others execute more than 3hour.

Solution:
This tool enumerates all jar files in specified dirs and then grouping 
them by approximate equal running time (the running time calculated for 
all methods in all classes)

Thanks,
Tatiana