Clean up test.
Add a test.
Add odebug() handler.
Add normalizePath().
Dereference argument in POSIXPath().

Without "contents of" a regression may occur when
we use POSIXPath in normalizePaths().
Fix splitPath() for short paths.

Fix splitPath() for short paths (e.g., "c/").
Adopt a semantics similar to File.basename() and
File.dirname() in Ruby.

Splitting a path should never give rise to an empty
string.
Coerce output messages to text.

This allows us to write, for example, ohai(1)
instead of ohai(1 as text).
Add debug() handler to test for debugging flag.
Update normalizePaths() to use POSIXPath().
Update joinPath() to use POSIXPath().
Update absolutePath() to use POSIXPath().
Simplify ditto().
Expand comment of glob() handler.
Add test for makeAlias().
Add deslash() handler.
Use application’s id instead of name.

Use application’s id to send events to (Apple)Script Editor, for better compatibility.