[HTML] Fix condition in handling of DISPID_COMMANDSTATECHANGE.

(coverity CID989766)
[THEME] Fix size_t argument of memset().

(coverity CID989743)
[TRELIST] Fix use after free().

(coverity CID989740)
[TREELIST] Unharmful change to silence coverity.

(coverity CID989741 and CID989742)
[PROPVIEW] Fix propview_set_propset().

 * propset_uninstall_view() got compeltely bad param.
 * propset_unref() got the new propset instead of the old one.

(coverity CID989763)
[PROPVIEW] Fix propview_setup_scrollbars() when propset is NULL.

(coverity CID989762)
[DSA] Fix error handling in dsa_insert_smart().

It could not work due to implicite int -> WORD casting.

(coverity CID989759)
[MDITAB] Fix hadling of item->img < 0 (e.g. MC_I_IMAGENONE).

(coverity CID989757, CID989758)
[DSA] Explicitely cast to size_t where appropriate.

(coverity CID989748, CID989749, CID989750, CID989751, CID989752,
CID989754).