add operator<, -, -=

stepmania/src/RageTimer.cpp

@@ -105,6 +105,13 @@ float RageTimer::operator-(const RageTimer &rhs) const
 	return Difference(*this, rhs);
 }
 
+bool RageTimer::operator<( const RageTimer &rhs ) const
+{
+	if( m_secs != rhs.m_secs ) return m_secs < rhs.m_secs;
+	return m_us < rhs.m_us;
+
+}
+
 RageTimer RageTimer::Sum(const RageTimer &lhs, float tm)
 {
 	/* tm == 5.25  -> secs =  5, us = 5.25  - ( 5) = .25

stepmania/src/RageTimer.h

@@ -29,11 +29,15 @@ public:
 
 	/* Add (or subtract) a duration from a timestamp.  The result is another timestamp. */
 	RageTimer operator+( float tm ) const;
+	RageTimer operator-( float tm ) const { return *this + -tm; }
 	void operator+=( float tm ) { *this = *this + tm; }
+	void operator-=( float tm ) { *this = *this + -tm; }
 
 	/* Find the amount of time between two timestamps.  The result is a duration. */
 	float operator-( const RageTimer &rhs ) const;
 
+	bool operator<( const RageTimer &rhs ) const;
+
 	/* "float" is bad for a "time since start" RageTimer.  If the game is running for
 	 * several days, we'll lose a lot of resolution.  I don't want to use double
 	 * everywhere, since it's slow.  I'd rather not use double just for RageTimers, since