Added support for some new environment variables within LLDB to enable some

extra launch options:

LLDB_LAUNCH_FLAG_DISABLE_ASLR disables ASLR for all launched processes

LLDB_LAUNCH_FLAG_DISABLE_STDIO will disable STDIO (reroute to "/dev/null")
for all launched processes

LLDB_LAUNCH_FLAG_LAUNCH_IN_TTY will force all launched processes to be
launched in new terminal windows.

Also, don't init python if we never create a script interpreter.

llvm-svn: 124341