* Fix undefined HRESULT codes in class CMapiApi in MapiApi.cpp.
* Fix doubled up sub-expressions in MIME and MAPI.
* Remove broken/unused morkRowCellCursor::MakeCell()
Tag #1273
* Part 1: make conversion CTORs explicit.
Minor tweaks to conform with new(ish) static analysis rule which flags up implicit single-argument conversion constructors.
* Part 2: fix a couple of double-mRefCnt declaration errors.
* Part 3: Fix unsafe use of NS_ConvertASCIItoUTF16().
Tag #1273