change amrnb decoder pointer exc to offset
change sp_enc pointer exc wsp to offset
change sp_enc pointer zero to offset
change sp_enc pointer error to offset
change sp_enc pointer h1 to offset
change sp_enc pointer speech and new_speech to offset
change sp_enc pointer p_window p_window_12k2 to offset
remove gain_idx_ptr from state, it should be used only in cod_amr
little modify, pointers to offsets
Merge branch 'develop'

get ready for v0.2.0