[DB] Adding relation many to many between Customers and IXPs
[IM] Sorting customer names in page header
[IM] Getting list of all customer wich are not related with given IXP
[IM] Filtering customer by ixp id
[NF] Customer filtered by IXP list
Merge branch 'master' into im-customer-ixps
[IM] Allow to choose initial IXP then adding a customer
[IM] Changing place of IPXs and Ifrastructure menu elements
[NF] Adding function to get IXP names list indexed by id
[BF] Removing unlink customer button
[IM] Adding IXP information to customer detail page
[NF] Allowing to limit customers by IXP
[BF] Using infrastructure short name instead of infrastructure number
[BF] Beter DQL to get un assinged customer for many-to-many relation.
[NF] Ading function to get unassigned IXPs to customer
[IM] Adding IXPs list to customer overview menu
[BF] Small bug fixes
[IM] Customer detail list can be filtered by ixp
[DB] Adding relation between Vlan and Infrastructure
[BF] Spelling