BZ1075293  KnowledgeAgent doesn't update kbase in Windows

KnowledgeAgentTest
- Added testModifyPackageUrlWithCache() for "drools.resource.urlcache" option.

UrlResourceTest
- Changed this.server = new Server(0); because it uses different ports every time start/stop. This affects all tests in this file but I guess it is the expected test.
- Fixed missing stream close in testWithCache(). If you miss to close the stream from the cache file, it will not be updated in Windows environment.
- Added  testWithCacheForSameInstance(). This is a variant of testWithCache(). But this test is a more realistic use case and can detect the issue in BZ1075293

Urlresource
- Windows fails on File.renameTo() when a target file exists.