Examples for OEM commands

A new file, named user_oem_examples.c has been added to the ipmc-user subdirectory of the ipmc-project GIT repository. It shows some examples for OEM functions and how to program them. Please contact xTCA support in case of doubt.

A new function, oem_get_macaddr, has been added to the examples and a bug was fixed in oem_get_sn and oem_get_bn