Remove a number of unneeded import os/bb calls

The bb and os modules are always imported so having these extra import calls
are a waste of space/execution time. They also set a bad example for people
copy and pasting code so clean them up.

(From OE-Core rev: 7d674820958be3a7051ea619effe1a6061d9cbe2)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/lib/oe/data.py

@@ -1,5 +1,4 @@
 import oe.maketype
-import bb.msg
 
 def typed_value(key, d):
     """Construct a value for the specified metadata variable, using its flags

meta/lib/oe/maketype.py

@@ -5,7 +5,6 @@ variable.  Other flags may be utilized in the construction of the types.  See
 the arguments of the type's factory for details.
 """
 
-import bb
 import inspect
 import types
 

meta/lib/oe/packagedata.py

@@ -1,5 +1,3 @@
-import os
-import bb.data
 import codecs
 
 def packaged(pkg, d):

meta/lib/oe/patch.py

@@ -1,6 +1,4 @@
 import oe.path
-import os
-import bb.utils, bb.msg, bb.data, bb.fetch2
 
 class NotFoundError(bb.BBHandledException):
     def __init__(self, path):

meta/lib/oe/path.py

@@ -1,7 +1,5 @@
-import bb
 import errno
 import glob
-import os
 import shutil
 import subprocess
 

meta/lib/oe/prservice.py

@@ -1,4 +1,3 @@
-import bb
 
 def prserv_make_conn(d, check = False):
     import prserv.serv

meta/lib/oe/terminal.py

@@ -1,5 +1,4 @@
 import logging
-import os
 import oe.classutils
 import shlex
 from bb.process import Popen, ExecutionError

meta/lib/oe/utils.py

@@ -1,5 +1,3 @@
-import bb, bb.data
-
 def read_file(filename):
     try:
         f = file( filename, "r" )