Accton 2014.05

Hi:
We have created a version for Accton AS5712-54X. Please review it.
I do not like this solution.  For starters we cannot have platform specific code in the ONIE core.

I think a better soln is to attack this where LSB_RELEASE_TAG is defined.  We can come up with a standard, generic variable like VENDOR_ONIE_VERSION.  If that variable is defined it can be assigned to LSB_RELEASE_TAG and then the rest just flow from there.