Fix some coverity and style issues in pnEncryption.

Sources/Plasma/NucleusLib/pnEncryption/plChecksum.cpp

@@ -119,6 +119,7 @@ plMD5Checksum::plMD5Checksum()
 
 plMD5Checksum::plMD5Checksum(const plMD5Checksum& rhs)
 {
+    memset(&fContext, 0, sizeof(fContext));
     memcpy(fChecksum, rhs.fChecksum, sizeof(fChecksum));
     fValid = rhs.fValid;
 }
@@ -135,6 +136,7 @@ plMD5Checksum::plMD5Checksum( hsStream* stream )
 
 void plMD5Checksum::Clear()
 {
+    memset(&fContext, 0, sizeof(fContext));
     memset(fChecksum, 0, sizeof(fChecksum));
     fValid = false;
 }
@@ -182,6 +184,7 @@ void plMD5Checksum::Finish()
 {
     MD5_Final(fChecksum, &fContext);
     fValid = true;
+    memset(&fContext, 0, sizeof(fContext));
 }
 
 const char* plMD5Checksum::GetAsHexString() const
@@ -245,6 +248,7 @@ plSHAChecksum::plSHAChecksum()
 
 plSHAChecksum::plSHAChecksum(const plSHAChecksum& rhs)
 {
+    memset(&fContext, 0, sizeof(fContext));
     memcpy(fChecksum, rhs.fChecksum, sizeof(fChecksum));
     fValid = rhs.fValid;
 }
@@ -261,6 +265,7 @@ plSHAChecksum::plSHAChecksum(hsStream* stream)
 
 void plSHAChecksum::Clear()
 {
+    memset(&fContext, 0, sizeof(fContext));
     memset(fChecksum, 0, sizeof(fChecksum));
     fValid = false;
 }
@@ -310,6 +315,7 @@ void plSHAChecksum::Finish()
 {
     SHA_Final(fChecksum, &fContext);
     fValid = true;
+    memset(&fContext, 0, sizeof(fContext));
 }
 
 const char* plSHAChecksum::GetAsHexString() const
@@ -371,6 +377,7 @@ plSHA1Checksum::plSHA1Checksum()
 
 plSHA1Checksum::plSHA1Checksum(const plSHA1Checksum& rhs)
 {
+    memset(&fContext, 0, sizeof(fContext));
     memcpy(fChecksum, rhs.fChecksum, sizeof(fChecksum));
     fValid = rhs.fValid;
 }
@@ -389,6 +396,7 @@ void plSHA1Checksum::Clear()
 {
     memset(fChecksum, 0, sizeof(fChecksum));
     fValid = false;
+    memset(&fContext, 0, sizeof(fContext));
 }
 
 void plSHA1Checksum::CalcFromFile(const plFileName& fileName)
@@ -436,6 +444,7 @@ void plSHA1Checksum::Finish()
 {
     SHA1_Final(fChecksum, &fContext);
     fValid = true;
+    memset(&fContext, 0, sizeof(fContext));
 }
 
 const char* plSHA1Checksum::GetAsHexString() const