Fix BHandler::GetSupportedSuites()

The logic was reversed accidentally in hrev47355

Rewrite the method to make more sense. If data is NULL return
B_BAD_VALUE right away. Otherwise set the status based on the first
operation, if that succeeds perform a second one, and return the
result.

Fixes CID 1222666
shortcut_catcher: Fix KeyCommandMap::_DeleteHKSList()

You can't increment the list item counter as you delete because the count
decreases as you go. Instead delete the first item until there are no more
items, then delete the list.
shortcut_catcher: style overhaul
Revert "shortcut_catcher: Fix KeyCommandMap::_DeleteHKSList()"

This reverts commit cb3243fbbd1f06f5c205c7cbc3a6911586d6cf9e.

Sorry, this might do bad things.
Shortcuts: use BPathFinder instead of find_directory. Fixes #9958.

* Previously, BPath::Append() would return an empty path if the
  path didn't exist (and an error); in a nightly image, the
  B_USER_ADDONS_DIRECTORY didn't exist, triggering the bug.
* Replaced the code with calls to BPathFinder instead, which takes
  care of the empty path automatically.
shortcut_catcher: A few 80 char limit fixes
shortcut_catcher: rename a couple variables

Fix build, msg => message

Fix warning use int32, not uint32

Also do a bit of refactoring.