Update store.c

fix for seg fault in pthreads_store_pop
Update store.c
Merge pull request #319 from bmewburn/master

Update store.c
Added sequence point in pthreads_store_chunk

Added sequence point to prevent ambiguous param evaluation order when calling zend_hash_get_current_key_ex inline with zend_hash_del_key_or_index.
Merge pull request #323 from bmewburn/master

Added sequence point in pthreads_store_chunk
fix #323 where ktype was no longer correctly set making chunk() key preservation fail.
Merge pull request #325 from 2072/#323-PR_fix

fix chunk() key preservation after #323