Support rgb_output_level option
BugFix: style setting NOT apply to scripts not containing a default script. [PART 1] CreateDefaultStyle may be called several times. While variable m_fUsingAutoGeneratedDefaultStyle's value is always false if CreateDefaultStyle being called more than once.
BugFix: style setting NOT apply to scripts not containing a default script. [PART 2] m_fUsingAutoGeneratedDefaultStyle is set to false in SetDefaultStyle so that we can NOT use it to decide should we apply style setting to script.
BugFix: style setting NOT apply to scripts not containing a default script. [PART 3] Append is complicated for variables like m_fUsingDefaultStyleFromScript should be compared and choose a right value carefully. Anyway we don't need it ...
BugFix: style setting NOT apply to scripts not containing a default script. [PART 4] Should reset m_fUsingDefaultStyleFromScript when CSimpleTextSubtitle resets
BugFix: style setting NOT apply to scripts not containing a default script. [PART 5] We do NOT want any others call CopyStyles
New Style setting dialog [PART 1] Change to use CPropertySheet for default style editing