removed FRAME_LENGTH_COMPLEX_SAMPLES from pcie_interface.h and adapted functions that were still using it
added gain control (only used by emos-raw at the moment)
emos-raw now supports multiple cards and has a scope


git-svn-id: http://svn.eurecom.fr/openair4G/trunk@5122 818b1a75-f10b-46b9-bf7c-635c3b92a50f