* either the default INIT_MOVE operator works ('=')
* either an INIT_MOVE method is defined
* or it is disabled.
As a consequence, fix usage of testobj_t and mpz_t in the repository
The emulation layer of INIT_MOVE using INIT_SET+CLEAR is removed:
it wasn't working correctly with the local memory context
(INIT_MOVE doesn't need any local memory context to work,
whereas INIT_SET/CLEAR does)
Remove macro M_DO_INIT_MOVE as it is now useless and uses M_CALL_INIT_MOVE.
The INIT_MOVE default method no longer sets the old 'src' to '0':
it was useless (it doesn't catch any error) and complicates compiler parsing.
Fix POD & A1 & CSTR & classic oplists definition (missing INIT_MOVE operators).