Modernize code for easier Python 3 port

- Replace print statement with function call
- Replace except ..., ...: syntax with except ... as ...:
- Simplify obsolete try ... except ... code block
- Replace some unicode calls with u-prefixed strings
- Do not use `len(SEQUENCE)` to determine if a sequence is empty
- Replace dictionary creation
- Drop support for GObject static bindings

misc/offsets.py

@@ -64,4 +64,4 @@ if len(line) > 11:
     line = line[:-2] + '"'
     lines.append(line)
 
-print "\n".join(lines)
+print("\n".join(lines))