BUG-1089: migrate InventoryReader

Migrates InventoryReader from xtend to pure Java.

Change-Id: I285c3dcbae8f407ec75de03d2df3092f9fcab30f
Signed-off-by: Robert Varga <rovarga@cisco.com>
BUG-1089: use a string constant for "::::"

This just makes sure the class is always consistent in naming things.

Change-Id: I442eec4204e9a5a7073e023bad7e392c2c56c1be
Signed-off-by: Robert Varga <rovarga@cisco.com>