libcompel: elf -- Add debug prints

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
libcompel: No need to implicitly prepand prologue

The prologue is linked during "pack" action.
Also a few fixes here and there.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
compel: Update docs

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>