Kernel printing: Improve iname ordering in output.

Closes #5

See merge request !82

# Conflicts:
#   loopy/kernel/__init__.py

This adds a tool for computing the iname nest efficiently, for printing.

Closes #5

Implement a syntax for no_sync_with scopes. (closes #67 on github)

See merge request !76

This reverts commit d51b2616.

Kernel printing: Print out items in natural order.

See merge request !81

Type inference: Avoid unnecessary expensive stringifications for

See merge request !80

debug messages when debugging is not enabled.

Only consider the parent's inames in deciding parent relation in domain tree (Fixes #78 on Github)

See merge request !79

Barrier insertion: Don't treat write-after-write self-dependencies as

See merge request !77

special (see #21 on gitlab).

This change should effectively be a no-op, since we don't insert
barriers for self-dependencies anyway.

# Conflicts:
#   test/test_loopy.py

Barrier insertion updates

See merge request !74

Better detection of dtype in TemporaryVariable initialization

See merge request !58

Next try at removing the ambiguous schedule warning

See merge request !65

insn_ids_reaching_*_without_interleaving_barrier().

Make the SCC unit test stricter.

See merge request !75

insn_ids_reachable_from_start_without_intervening_barrier(): Can further narrow set of instructions by considering barriers at the shallower level.