Dropping binaries onto the phone

[Daniel van Vugt]

I only noticed yesterday that when a change is cross-compiled for armhf 
even in the lp:mir/0.5 tree (my phone has Mir 0.5.1) that the resulting 
binaries just made Unity8 crash. This is obviously not right because I 
had chosen the 0.5 series with the same Mir ABI levels as the phone is 
using.

Now today utopic got an update and changed the cross compiler from gcc 
4.8 to 4.9. This seems to have solved the ABI compatibility issues and 
Unity8 now runs fine with custom experimental Mir binaries.

So,
   1. Update your utopic build machine.
   2. Make sure your cross compiler is now version 4.9.*
   3. Build against the Mir series installed on your device (lp:mir/0.5, 
lp:mir/0.6).

Finally the resulting binaries will be drop-in compatible with phablet 
images. No silos, PPAs, or on-device builds are necessary. :)