Bug 1147283 - Replace mozpack.path with mozpath. r=mshal

Back when mozpack.path was added, it was used as:

  import mozpack.path
  mozpack.path.func()

Nowadays, the common idiom is:

  import mozpack.path as mozpath
  mozpath.func()

because it's shorter.

$ git grep mozpath\\. | wc -l
423
$ git grep mozpack.path\\. | wc -l
123

This change was done with:
$ git grep -l mozpack.path\\. | xargs sed -i 's/mozpack\.path\./mozpath./g'
$ git grep -l 'import mozpack.path$' | xargs sed -i 's/import mozpack.path$/\0 as mozpath/'
$ (pat='import mozpack.path as mozpath'; git grep -l "$pat" | xargs sed -i "1,/$pat/b;/$pat/d")

tools/mach_commands.py

@@ -174,7 +174,7 @@ class UUIDProvider(object):
         import os
         import xpidl
         from mozpack.files import FileFinder
-        import mozpack.path
+        import mozpack.path as mozpath
         from tempfile import mkdtemp
 
         finder = FileFinder(path, find_executables=False)
@@ -184,7 +184,7 @@ class UUIDProvider(object):
             parser = xpidl.IDLParser(outputdir=tmpdir)
             registry = InterfaceRegistry()
             for p, f in finder.find('**/*.idl'):
-                p = mozpack.path.join(path, p)
+                p = mozpath.join(path, p)
                 try:
                     content = f.open().read()
                     idl = parser.parse(content, filename=p)