Pushing toward alpha.

This commit is for ease of transfer to my desktop PC for proper
testing. (This mac hardly runs the game itself.) Most of it is not
quite functional, but some is.
Fixed some errors preventing testing.
Fixed some errors preventing testing.
Small tweaks to worldgen to help counter stutter.

Currently still does not alleviate it.
Attempting to reduce number of entities in the world.
fixed entity count explosion
Scarecrow crash fix.
Fixed main menu crash.
added entity_count_profiling.txt to .gitignore
Added tracing capabilities to debugtools.lua
Slightly better formatting for trace.txt
Updated rc.defaults.lua
I had forgotten the MODROOT in trace_flow()!
cleaned up the profiler
Changed the tracer behaviour in platforms other than Linux
Changed the tracer behaviour in platforms other than Linux (2)
Improved tracer output a bit
Trying to fix the empty trace.txt
Disabled main screen alterations for now and fixed trace_flow()
disabled the file reopening scheme from the tracer