Fix 64bit runtime in 32bit mode.

Fixes #40.
32bit compile can now successfully pass all tests.
Noted one memory leak in unique_mapping().
Extensive 64bit LPC Tests improvments.
Extended various sprintf buffer, to avoid crashes when printing out
numbers and floats.
Extended buffer in dump_trace.
Merge pull request #53 from sunyc/master

Fixes compiling and tests under 32bit mode.
Fluffos now provides a 64bit LPC runtime in both cases.