rename DEBUG define to TINYXML2_DEBUG

The original name is to general. This prevents possible name collisions with other defines, enums, etc. from projects where tinyxml2 is used.

setversion.py

@@ -135,7 +135,7 @@ def cmakeRule2( line ):
 fileProcess( "CMakeLists.txt", cmakeRule2 )
 
 print( "Release note:" )
-print( '1. Build.   g++ -Wall -DDEBUG tinyxml2.cpp xmltest.cpp -o gccxmltest.exe' )
+print( '1. Build.   g++ -Wall -DTINYXML2_DEBUG tinyxml2.cpp xmltest.cpp -o gccxmltest.exe' )
 print( '2. Commit.  git commit -am"setting the version to ' + versionStr + '"' )
 print( '3. Tag.     git tag ' + versionStr )
 print( '   OR       git tag -a ' + versionStr + ' -m [tag message]' )