Multiple small improvements to threads:
+=over 4
+
+=item *
+
Change the internal structured of thread->params from an SV (RV) to an AV
- so we now pass around and store the array directly, rather than creating,
holding and dereferencing a reference to it (78b7eff).
+=item *
+
Change S_ithread_create() params from a single AV* to a pair of SV** pointers.
This saves creating, duplicating and freeing and AV, which is only ever used for
an internal calling convention (4cf5ea).
-Remove redundant hv_exists() calls from ithread_create()'s spec parser (b1faab).
-
-Skip unnecessary newAV() in ithread_create() (39f3f7).
+=item *
-=over 4
+Remove redundant hv_exists() calls from ithread_create()'s spec parser (b1faab).
=item *
-XXX
+Skip unnecessary newAV() in ithread_create() (39f3f7).
=back