Merge pull request #74 from yenatch/master

Thing to build symfiles. Use with bgb or another debugger.
saner import syntax in preprocessor
make the preprocessor a little faster

This reduced the preprocessing time from 8s to 2.7s.
even faster preprocessor
disable '; original line' by default
make include_file faster in the preprocessor
disable macro error checking by default
combine multiple calls to sys.stdout.write
speed up text conversion in preprocessor
comment LoadEnemyMon and related fns; add RNG fns