OpenFileDlg: Avoid creating an empty CPath object.
SubtitleDlDlg: Controls handles aren't initialized yet in the constructor.
STS: Code simplification.
Auto-update: Show the message at first start before starting playing anything.
RealMediaGraph: Fix a typo.
About dialog: Increase "Copy to clipboard" button size for translations.
Updated German translation.
AudioSwitcher: Fix the initialization of the normalization factor.

The variable m_normalizeFactor depends of m_nMaxNormFactor in the initialization list so the declaration order has to take that into account.
AudioSwitcher: Use the defines for the max and min values of a 24-bit integer.
BaseSplitterFileEx: Fix an incorrect check.

This check was always false.
BaseSplitterFileEx: Simplify a check.

h.bitpersample is unsigned, checking if it's greater than 0 will always be true.
BufferFilter: Check for null pointers before actually using them.
ComPropertySheet: Remove a redundant check.
FGManagerBDA: Check for null pointer before actually using it.
IPinHook: Fix wrong sizeof.
PPageFileInfoClip: Use CComBSTR Length method when possible.
Make CHdmvClipInfo::Stream* const.
Merge identical ifs.
Change__int64 to REFERENCE_TIME when it's more appropriate.
cosmetics: reindent files.