Remove unused constant max_layer, which is also incorrectly defined as UCHAR_MAX when layer_t is uint32_t

Defining it using std::numeric_limits<layer_t>::max() would of avoided
this inconsistancy but as it unused it is doesn't really matter I guess.


git-svn-id: svn://localhost/ardour2/trunk@2392 d708f5d6-7413-0410-9779-e7cbd77b26cf

libs/ardour/ardour/ardour.h

@@ -51,8 +51,6 @@ namespace ARDOUR {
 	
 	std::string get_ardour_revision ();
 
-	const layer_t max_layer = UCHAR_MAX;
-
 	microseconds_t get_microseconds ();
 
 	Change new_change ();