Performance fixes

[Dinesh-Khandelwal]

The main intention of these fixes:

1. Use single xmlcontext object to use descriptor caching properly.
   2.Avoid checking .contains for descriptors while putting into the cache as it casues memory leaks if .cdr files are not proper e.g. in different jars but in the same name space but with different entries.
2. Search with the right pattern of the descriptors in the first go to avoid thread blocks on the class loader.

[Dinesh-Khandelwal]

#61

[Dinesh-Khandelwal]

I hope that , you will not get any formatting issue now.