Determine debug builds by looking for a magic file

If .debug exists, then we'll compile as a debug build.  This will let me
toggle debug status during development without needing to worry about
committing the change.

Signed-off-by: Anna Schumaker <Anna@OcarinaProject.net>

.gitignore

@@ -13,3 +13,4 @@ bin/
 core.*
 html/
 latex/
+.debug

Sconstruct

@@ -1,12 +1,11 @@
 #!/usr/bin/python
 import os
 
-# Configuration variables
 CONFIG_VERSION = "6.3"
-CONFIG_DEBUG   = True
 
 
 # Set up default environment
+CONFIG_DEBUG   = os.path.exists(".debug")
 CONFIG_CCFLAGS = [ "-O2" ]
 if CONFIG_DEBUG == True:
 	CONFIG_CCFLAGS = [ "-Wall", "-Werror", "-g", "-DCONFIG_DEBUG" ]