Added the ability to run a process in a shell on MacOSX currently when using

the --tty option. So you can now get shell expansion and file redirection:

(lldb) process launch --tty --shell -- *.jpg < in.txt > out.txt

Again, the "--tty" is mandatory for now until we hook this up to other 
functions. The shell is also currently hard coded to "/bin/bash" and not the
"SHELL" variable. "/bin/tcsh" was causing problems which I need to dig into.

llvm-svn: 144443