Change hard tabs in TAS files to four spaces
Depend on a mended tinypp
Use `struct element` for `struct instruction`

This was changed as of b924d3f7.
Make compatible with opaque `struct param`

The `struct param` type became opaque as of d7d53eb7.
Stop using aggregate types in va_arg()

emscripten can't handle this yet, and we don't need to. Use pointers.
Declare strdup() when -DEMSCRIPTEN
Mending issues with re-running in browser
Embed -> preload, explicit paths
Make tcc (tinypp) work again

See comments in Makefile.
Ignore files generated by --preload-file
Build works with DEBUG=1 and without
Remove obsolete file
Closure-compilation now mostly works

It has to stay disabled for now, though ; otherwise we get errors like
this :

	cannot dynamically allocate, sbrk now has control (tcc.js, line 29)
	cannot dynamically allocate, sbrk now has control (tcc.js, line 30)

which prevent correct initialisation.
Reduce height of textareas, 30 -> 20 rows
Use one _pre.js wrap file
Generalise pre- and post-files

Make dependencies work [better ?] too.
Ignore generated *_post.js files
Rename tasdata -> tenyr_state
Now tsim can run multiple times per page load

Previously, tsim could be run only once per page load, because it was
closing its input stream and not resetting the EOF indicator.
Make in-place sed work on GNU/non-GNU sed