Description of problem:
If you add a macpool via API the case of the macaddress is preserved.
It is exected that the mac address is streamlined in the output

Version-Release number of selected component (if applicable):
RHEV 3.6

How reproducible:
always

Steps to Reproduce:
1. Add a macpool with small and capital letters in the macaddress as follows:
[root@ovirt xml]# cat macpool_new.xml 
<mac_pool>
    <name>Testpool</name>
    <description>My Testpool</description>
    <allow_duplicates>false</allow_duplicates>
    <ranges>
        <range>
            <to>00:1a:4B:01:00:00</to>
            <from>00:1a:4c:FF:FF:FF</from>
        </range>
    </ranges>
</mac_pool>

[root@ovirt xml]# curl -s -k -u 'admin@internal:password' -X POST 'Accept: application/xml' -H 'Content-type: application/xml' -d @/root/xml/macpool_new.xml https://ovirt.satellite.local/ovirt-engine/api/macpools
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<mac_pool href="/ovirt-engine/api/macpools/2a6b90af-7c1b-43ff-a740-1264fa17f94d" id="2a6b90af-7c1b-43ff-a740-1264fa17f94d">
    <name>Testpool</name>
    <description>My Testpool</description>
    <allow_duplicates>false</allow_duplicates>
    <default_pool>false</default_pool>
    <ranges>
        <range>
            <from>00:1a:4c:FF:FF:FF</from>
            <to>00:1a:4B:01:00:00</to>
        </range>
    </ranges>
</mac_pool>
[root@ovirt xml]# 
2. Check the content in the macpool (again with curl):
[root@ovirt xml]# curl -s -k -u 'admin@internal:password' https://ovirt.satellite.local/ovirt-engine/api/macpools/<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<mac_pools>
    <mac_pool href="/ovirt-engine/api/macpools/0000000d-000d-000d-000d-000000000259" id="0000000d-000d-000d-000d-000000000259">
        <name>Default</name>
        <description>Default MAC pool</description>
        <allow_duplicates>false</allow_duplicates>
        <default_pool>true</default_pool>
        <ranges>
            <range>
                <from>00:1A:4A:16:01:51</from>
                <to>00:1A:4A:16:01:e6</to>
            </range>
        </ranges>
    </mac_pool>
    <mac_pool href="/ovirt-engine/api/macpools/2a6b90af-7c1b-43ff-a740-1264fa17f94d" id="2a6b90af-7c1b-43ff-a740-1264fa17f94d">
        <name>Testpool</name>
        <description>My Testpool</description>
        <allow_duplicates>false</allow_duplicates>
        <default_pool>false</default_pool>
        <ranges>
            <range>
                <from>00:1a:4c:FF:FF:FF</from>
                <to>00:1a:4B:01:00:00</to>
            </range>
        </ranges>
    </mac_pool>
</mac_pools>
[root@ovirt xml]# 

Actual results:
The Macaddress is case preserved as: 00:1a:4c:FF:FF:FF

Expected results:
The Macaddresses should be always the same case (preferrably lower case), e.g. 00:1a:4c:ff:ff:ff

Additional info: