Don't suppress IO errors when writing files

* Close or flush streams explicitely so writing is not
  deferred
    * to catch errors in the right place
    * to avoid suppressing errors completely when writing
      would be deferred to the destructor invocation
* Improve comments

CMakeLists.txt

@@ -10,7 +10,7 @@ set(META_APP_URL "https://github.com/${META_APP_AUTHOR}/${META_PROJECT_NAME}")
 set(META_APP_DESCRIPTION "C++ library to read/write passwords from/to encrypted files")
 set(META_VERSION_MAJOR 5)
 set(META_VERSION_MINOR 0)
-set(META_VERSION_PATCH 1)
+set(META_VERSION_PATCH 2)
 set(META_ADD_DEFAULT_CPP_UNIT_TEST_APPLICATION ON)
 
 # add project files

io/passwordfile.cpp

@@ -507,6 +507,7 @@ void PasswordFile::write(PasswordFileSaveFlags options)
     if (!(options & PasswordFileSaveFlags::Encryption)) {
         // write data to file
         m_file.write(decryptedData.data(), static_cast<streamsize>(size));
+        m_file.flush();
         return;
     }
 
@@ -560,6 +561,7 @@ void PasswordFile::write(PasswordFileSaveFlags options)
     }
     m_file.write(reinterpret_cast<char *>(iv), aes256cbcIvSize);
     m_file.write(encryptedData.data(), static_cast<streamsize>(outlen1 + outlen2));
+    m_file.flush();
 }
 
 /*!