[1/11] apphelp: Implement SdbTagToString.
[2/11] apphelp: Implement SdbCloseDatabase.
[3/11] apphelp: Implement SdbGetTagFromTagID.
[4/11] apphelp: Implement SdbGetFirstChild.
[5/11] apphelp: Implement SdbGetNextChild.
[6/11] apphelp: Implement SdbOpenDatabase.
[7/11] apphelp: Implement SdbReadStringTag.
[8/11] apphelp: Implement SdbReadDWORDTag.
[9/11] apphelp: Implement SdbReadQWORDTag.
[10/11] apphelp: Implement SdbGetStringTagPtr.
[11/11] apphelp: Add tests.
apphelp: Implement SdbCreateDatabase and SdbCloseDatabaseWrite
apphelp: Implement SdbGetBinaryTagData.
apphelp: Add stub for SdbOpenApphelpResourceFile.
apphelp: Implement SdbWriteDWORDTag and refactor some code
apphelp: Implement SdbWriteQWORDTag.
apphelp: Implement SdbWriteStringTag
apphelp: Implement SdbWriteWORDTag
apphelp: Add more tests
apphelp: Implement SdbWriteNULLTag