Initial performance under ANTLR:

  short slab of ASCII text   14.380000   2.240000  16.620000 ( 16.685454)
  short slab of UTF-8 text   18.080000   2.420000  20.500000 ( 21.965856)

After move to Ragel scanner:

  short slab of ASCII text    5.010000   0.010000   5.020000 (  5.033520)
  short slab of UTF-8 text    9.130000   0.010000   9.140000 (  9.158980)

  About 28% of time is being spent inside rb_ary_includes
  (compared with only 14% in the next_token function)

After adding custom C replacement for Ruby Array class:

  short slab of ASCII text    3.400000   0.000000   3.400000 (  3.417410)
  short slab of UTF-8 text    6.290000   0.010000   6.300000 (  6.314861)

  Biggest drain is st_init_strtable (42%), something to do with string
  followed by 14% for rb_str_append
  (next_token function now up to 22%)

Add notes file to benchmarks subdirectory
Add notes file to benchmarks subdirectory

This will help keep track of performance improvements as I make further
optimizations.

Signed-off-by: Wincent Colaiuta <c76ac2e9cd86441713c7dfae92c451f3e6d17fdc@wincent.com>
