common: adds copy/move constructors and assignment operators to sixtrack::Buffer
common: adds copy/move constructors and assignment operators to sixtrack::Buffer

Note: so far, copy and move overload set has been (mostly) disabled for
      the C++ interface to NS(Buffer); This is an attempt to enable the interface
      for those cases where it makes sense (i.e. where the underlying memory
      structure acutally allows copying and especially moving).

      In case of corner cases where it is not possible to perform some meaningful
      operations, exception(s) are thrown. This is not optimal and only a stop-
      gap measurement. Eventually, the capabiltiy and restriction model of the
      Buffer implementations should be revised to reduce the number of
      corner cases that have to be handled.

WARNING This has not been tested yet!!!
TODO Write unit-tests covering these operations

SixTrack/SixTrackLib,SixTrack/SixTrackLib,SixTrack/SixTrackLib,SixTrack/SixTrackLib