initial draft of optimizer, inactive ATM.
working build, lots of debug output, more intelligence.
nqp-jvm doesn't like negative nums in substr
this should have been gone already.
little improvements. actually finds symbols now.
removed debug output
Merge pull request #115 from dwarring/master

thinko on unicode surrogate range
fix sprintfdirectives, which returns an int
Add rule for running individual test files.
Merge branch 'master' of github.com:perl6/nqp
Add generic type to remove compiler warning.
Add rule for running individual test files to parrot Makefile.
First tests for file ops, plus fixes on JVM.
Fix typo in last Makefile commit.
Merge branch 'origin/nqp-optimizer'

This gives us an optimizer for NQP that removes some int to num and
num to int coercions if they are superfluous.
Make nqp::shell respect the 3 argument on linux.
Pass the env variables on windows.
Added nqp::readfh on JVM. Fixes / cleanup of nqp::writefh impl.
Attempt at corretly passing the env variables on windows.
Use real \0