Bypass-02.testie: Clean up a bit

- use => connector on 'is' input for clarity

- is[xyz] are not used, so remove

- 'child1a' and 'child2a' do not have a parent, so rename to 'bp1a' and
  'bp2a' resp.

Signed-off-by: Patrick Verkaik <patrick@meraki.net>
Bypass-02.testie: Show Bypass traversal failure

This testie currently fails:
  Bypass-02.testie:241: file OUT has unexpected value starting at line 180
  Bypass-02.testie:241: OUT:180: expected '<end of file>'
  Bypass-02.testie:241: OUT:180: but got  'bp2b_1:    4 |  none'

It is fixed in the next few commits.

Signed-off-by: Patrick Verkaik <patrick@meraki.net>
Bypass: Some cleanup

- Replace tabs with whitespace since these files are mostly
  whitespace-indente.

- Add some comments so the populace can follow.

- Locator(int port) makes more sense than Locator(bool active) since
  Bypass doesn't always pass _active to it and the argument always
  corresponds to a port.

- In the "Assigning %arg1 to %arg2" chatter, switch the arguments to
  make more sense.

Signed-off-by: Patrick Verkaik <patrick@meraki.net>
Bypass: Fix Locator traversing bug

When visiting a Bypass element, Locator::visit() sets _port to the port
it wishes to traverse through and then, while visiting the Bypass's
children, checks that it's in the child connected to that port.  If it's
in the right child and that child is not a Bypass, it assigns _e and
_port as the final result and attempts to finish the traversal by
returning false.

However, returning false from visit() only ensures that the traversal
doesn't continue through the current element; traversal through the
*parent* Bypass element may not have completed, and it may visit further
siblings.  When traversal visits a next sibling, _port has been
clobbered, and so it's possible for Locator::visit() to consider the
sibling when it shouldn't.

This commit fixes the bug by storing the port to check in a separate
variable, _from_port, and using _port to only store the result.

Signed-off-by: Patrick Verkaik <patrick@meraki.net>
Merge pull request #115 from trackpick/fix-bypass-traversal

Fix bypass traversal