-x, -v for llgo-dist + tweaks to make llgo-dist and some (but not all) of llgo's unit tests succeed on Darwin

There are a couple of unit-tests still failing, but I'll need to set up a linux vm first for comparison.

Trying to compile the traditional hello world using just ```println``` works fine, but when using ```fmt.Println``` I get unresolved externals:

```
$ llgo-build hello.go
2013/09/16 20:05:03 building main
Undefined symbols for architecture x86_64:
  "_runtime.go", referenced from:
      _time.goFunc in hello-W1wd98.o
  "_sync.runtime_Syncsemacquire", referenced from:
      _sync.*Cond.Wait in hello-W1wd98.o
  "_sync.runtime_Syncsemcheck", referenced from:
      ___llgo.ctor.sync.0 in hello-W1wd98.o
  "_sync.runtime_Syncsemrelease", referenced from:
      _sync.*Cond.signalImpl in hello-W1wd98.o
  "_syscall.runtime_AfterFork", referenced from:
      _syscall.forkAndExecInChild in hello-W1wd98.o
  "_syscall.runtime_BeforeFork", referenced from:
      _syscall.forkAndExecInChild in hello-W1wd98.o
ld: symbol(s) not found for architecture x86_64
clang-3.3: error: linker command failed with exit code 1 (use -v to see invocation)
2013/09/16 20:05:20 open /var/folders/n1/yjqlqd2s04x7th1152h48hsr0000gn/T/llgo635367759/hello.bc: no such file or directory
```

Grepping for AfterFork it's nowhere to be found in llgo, so maybe this is a variant of #43?