Add xml parsing utils for mtn nigeria transport
Change the xml over tcp protocol to use the new xml utils (which use twisted.web.microdom)
Add a test to the xml over tcp protocol for asserting tolerance of chars considered invalid in xml
Remove stray debug line
Scrub details in new xml over tcp protocol test
Use simpler and specialised xml parsing instead of complicated generic parsing for xml over tcp protocol
Remove stray timeout debug statement
Handle cases where a node may have multiple text nodes for xml over tcp protocol
Remove the no longer needed empty child node case for xml over tcp protocol packet deserializing
Merge branch 'develop' into feature/issue-689-handle-bad-characters-better-in-mtn-ng-transport
Merge branch 'feature/issue-689-handle-bad-characters-better-in-mtn-ng-transport' into develop