examples/lamutex/orig.da: use 'timemax' as timeout value instead of 'None'.
incgen: mangle names to avoid name conflict.

In the inc module, process field names and function local names are all
turned into global names, so these names should be mangled to prevent
name clash.

* da/compiler/incgen.py:

  -(Options): new global var to store command line options.

  -(Counter): new global var for unique names.

  -(mangle_name): new function, generates mangled name for a given name
   object.

  -(gen_update_stub): new function, generates update stubs and
   calls (refactored from `gen_inc_module`).

  -(gen_assign_stub): argument 'jbstyle' removed; now generates stub
   call ast as well(refactored from `gen_inc_module`)

  -(gen_reset_stub, gen_init_event_stub): argument 'jbstyle' removed.

  -(gen_inc_module): argument `cmdline_args` is now the argument
   namespace object instead of a dict; set global var Options;
   refactored to use `gen_update_stub` and `gen_assign_stub`.

  -(IncInterfaceGenerator): read options values from global `Options`
   instead of self attributes; new parameter `mangle_names`; new
   parameter `last_freevars`.

  -(IncInterfaceGenerator.visit_NamedVar): mangle names specified in
   `mangle_names`.
Move 'tools' package to 'da.tools'.

To avoid package name conflict.