Increase test coverage brick/initiator/connector

Covered next methods:
	disconnect_volume_multipath_iscsi;
	get_multipath_iqn;
	get_iscsi_devices;
	get_multipath_device_name;

Change-Id: I0eaffa6d1408446f1f13e56016642df5337015a2
Remove unused methods from cinder.utils

These methods were left over from the split from Nova and are unused still.

Remove methods:
	fetchfile()
	trycmd()
	generate_uid()
	last_octet()
	get_my_linklocal()
	parse_mailmap()
	str_dict_replace()
	flatten_dict()

Change-Id: I5d41dec66246814bb1edb6f4993d5307587a00f9
Merge "Remove unused methods from cinder.utils"
Merge "Increase test coverage brick/initiator/connector"