Minor improvements

Some minor improvements:

1 - Using nowait version of rte_eth_link_get() function to avoid blocking operations that stalls the display updates
2 - Fixing segfault in wr_coremap that causes the "page cpu" to not display properly.
3 - Adding support for varying source/destination MAC addresses
4 - Removing unneeded hugepage files so that memory can be shared with other apps
5 - Removing VLAN as an ether-type