Added app.report_each_app().

Calls app:report() on each app.
LoadGen: Updated to work the new app API.

Example:

    # ./snabbswitch designs.loadgen.loadgen apps/ipv6/selftest.cap.input 0000:05:00.1 0000:8a:00.1
    Waiting for linkup. ok
    Waiting for linkup. ok
    Transmissions (last 1 sec):
    0000:05:00.1    TXDGPC (TX packets)     5,555,035       GOTCL (TX octets)       566,509,228
    0000:8a:00.1    TXDGPC (TX packets)     5,562,714       GOTCL (TX octets)       567,267,638
    Transmissions (last 1 sec):
    0000:05:00.1    TXDGPC (TX packets)     10,246,367      GOTCL (TX octets)       1,045,086,878
    0000:8a:00.1    TXDGPC (TX packets)     10,246,082      GOTCL (TX octets)       1,045,065,138
    Transmissions (last 1 sec):
    0000:05:00.1    TXDGPC (TX packets)     10,246,077      GOTCL (TX octets)       1,045,063,166
    0000:8a:00.1    TXDGPC (TX packets)     10,246,277      GOTCL (TX octets)       1,045,085,438

Fixes #128.
support register sets
fill/create/dump packets to/from binary and hex strings
MAC address object
indexed set, to ensure reuse of limited resources
better reports by main app loop
single driver for straight and VMDq apps
Merged Javier's new Intel 82599 driver with VMDq support.
loadgen: Updated for the new intel10g driver.
Merge branch 'master' of https://github.com/SnabbCo/snabbswitch