Bug 1487082 - Resolve potential for build bustage regarding bad implicit conversion constructors

* 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

db/mork/src/morkAtom.h

@@ -284,7 +284,7 @@ public:
 
 public: // empty construction does nothing
   morkWeeBookAtom() { }
-  morkWeeBookAtom(mork_aid inAid);
+  explicit morkWeeBookAtom(mork_aid inAid);
   
   void InitWeeBookAtom(morkEnv* ev, const morkBuf& inBuf,
     morkAtomSpace* ioSpace, mork_aid inAid);

db/mork/src/morkBead.h

@@ -62,7 +62,7 @@ public: // morkNode virtual methods
   virtual ~morkBead(); // assert that CloseBead() executed earlier
   
 public: // special case for stack construction for map usage:
-  morkBead(mork_color inBeadColor); // stack-based bead instance
+  explicit morkBead(mork_color inBeadColor); // stack-based bead instance
   
 protected: // special case for morkObject:
   morkBead(const morkUsage& inUsage, nsIMdbHeap* ioHeap,

db/mork/src/morkDeque.h

@@ -41,9 +41,9 @@ public:
   morkNext*  mNext_Link;
   
 public:
-  morkNext(int inZero) : mNext_Link( 0 ) { }
+  explicit morkNext(int inZero) : mNext_Link( 0 ) { }
   
-  morkNext(morkNext* ioLink) : mNext_Link( ioLink ) { }
+  explicit morkNext(morkNext* ioLink) : mNext_Link( ioLink ) { }
   
   morkNext(); // mNext_Link( 0 ), { }
   
@@ -118,7 +118,7 @@ public:
   morkLink*  mLink_Prev;
   
 public:
-  morkLink(int inZero) : mLink_Next( 0 ), mLink_Prev( 0 ) { }
+  explicit morkLink(int inZero) : mLink_Next( 0 ), mLink_Prev( 0 ) { }
   
   morkLink(); // mLink_Next( 0 ), mLink_Prev( 0 ) { }
   

db/mork/src/morkFactory.h

@@ -160,7 +160,7 @@ public: // morkFactory virtual methods
   
 public: // morkYarn construction & destruction
   morkFactory(); // uses orkinHeap
-  morkFactory(nsIMdbHeap* ioHeap); // caller supplied heap
+  explicit morkFactory(nsIMdbHeap* ioHeap); // caller supplied heap
   morkFactory(morkEnv* ev, const morkUsage& inUsage, nsIMdbHeap* ioHeap);
   void CloseFactory(morkEnv* ev); // called by CloseMorkNode();
   

db/mork/src/morkNode.h

@@ -56,7 +56,7 @@ public:
   mork_usage     mUsage_Code;  // kHeap, kStack, kMember, or kGhost
   
 public:
-  morkUsage(mork_usage inCode);
+  explicit morkUsage(mork_usage inCode);
 
   morkUsage(); // does nothing except maybe call EnsureReadyStaticUsage()
   void InitUsage( mork_usage inCode)
@@ -163,7 +163,7 @@ public: // morkNode memory management operators
 protected: // construction without an anv needed for first env constructed:
   morkNode(const morkUsage& inUsage, nsIMdbHeap* ioHeap);
 
-  morkNode(mork_usage inCode); // usage == inCode, heap == nil
+  explicit morkNode(mork_usage inCode); // usage == inCode, heap == nil
 
 // { ===== begin basic node interface =====
 public: // morkNode virtual methods

db/mork/src/morkParser.cpp

@@ -119,7 +119,7 @@ morkParser::morkParser(morkEnv* ev,
 , mParser_ColumnSpool(ev, &mParser_ColumnCoil)
 , mParser_StringSpool(ev, &mParser_StringCoil)
 
-, mParser_MidYarn(ev, morkUsage_kMember, ioSlotHeap)
+, mParser_MidYarn(ev, morkUsage(morkUsage_kMember), ioSlotHeap)
 {
   if ( inBytesPerParseSegment < morkParser_kMinGranularity )
     inBytesPerParseSegment = morkParser_kMinGranularity;

db/mork/src/morkRow.h

@@ -95,7 +95,7 @@ public: // flags bit twiddling
 
 public: // other row methods
   morkRow( ) { }
-  morkRow(const mdbOid* inOid) :mRow_Oid(*inOid) { }
+  explicit morkRow(const mdbOid* inOid) :mRow_Oid(*inOid) { }
   void InitRow(morkEnv* ev, const mdbOid* inOid, morkRowSpace* ioSpace,
     mork_size inLength, morkPool* ioPool);
     // if inLength is nonzero, cells will be allocated from ioPool