Patch for minidom's writexml has been added

* patch applied only for python < 2.7.3
* unit tests added for patch and xml conf generator
* it has been tested at python 2.6.7, 2.7.2-2.7.4

Fixes: bug #1174841

Change-Id: I6db89a06a4fa86b62a582d0188d0b7f1a508dcd2
Merge "Patch for minidom's writexml has been added"