systemtap prototype #3.3

- demonstrates parsing of hypothetical systemtap script
  language using hand-written simpe LL(1) recursive-descent parser
  and similar little lexer: parse.cxx, parse.h
- semantic analysis in elaborate.cxx; translation in translate.cxx;
  driven from main.cxx
- examples under testsuite/*
- "probe", "global", "function" top-level constructs parsed
- some tapset library auto-inclusion supported
- use autotools-style configure; make; make check
- to see parse tree: stap -p1 -e 'SCRIPT FRAGMENT'
- to see semantic/type analysis results: stap -p2 -e 'SCRIPT FRAGMENT'
- to see translation of constructs: stap -e 'SCRIPT FRAGMENT';
  try compiling result with "gcc -c"!