Refactoring EditUdevRulesDialog

Removed YCP -> Ruby artifacts.
Dry the code:
- Introduced local variables.
- Slightly modified workflow.
Separated EditUdevName dialog into own class.
Changed layout of "Edit nic name" dialog.

Changed order of widgets. Different handling of name input (no checkbox)
name change is based on old and new name comparison.
Added comments into EditNicName class
Updated changelog
Reformated test/Makefile.am
Added testsuite for "edit nic name" dialog.

The testsuite is written in rspec which is currently not available in
OBS. If you want to run it add the file name into test/Makefile.am
Updated formating according SUSE style guide.
Moved exception handling from EditNicName at top level
Merge pull request #114 from mchf/refactoring-EditUdev-dialog

Refactoring edit udev dialog