Add "DispatchKeyValueInt" stock

[Psykotikism]

Closes #1761

[Mart-User]

Thank you! I hope it merges.

[Wend4r]

I suggest adding 2 more stock functions by Vector and float as in the games code

bool CBaseEntity::KeyValue( const char *szKeyName, float flValue ) 
{
	char	string[256];

	Q_snprintf(string,sizeof(string), "%f", flValue );

	return KeyValue( szKeyName, string );
}

bool CBaseEntity::KeyValue( const char *szKeyName, int nValue ) 
{
	char	string[256];

	Q_snprintf(string,sizeof(string), "%d", nValue );

	return KeyValue( szKeyName, string );
}

bool CBaseEntity::KeyValue( const char *szKeyName, const Vector &vecValue ) 
{
	char	string[256];

	Q_snprintf(string,sizeof(string), "%f %f %f", vecValue.x, vecValue.y, vecValue.z );

	return KeyValue( szKeyName, string );
}

[asherkin]

Thanks, LGTM.