buildman: Move to absolute imports

At present buildman sets the python path on startup so that it can access
the libraries it needs. If we convert to use absolute imports this is not
necessary.

Move buildman to use absolute imports. Also adjust moveconfig.py too since
it uses some buildman modules and cannot work without this.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/buildman/test.py b/tools/buildman/test.py
index 8b6d138..87175ee 100644
--- a/tools/buildman/test.py
+++ b/tools/buildman/test.py
@@ -13,15 +13,15 @@
 our_path = os.path.dirname(os.path.realpath(__file__))
 sys.path.append(os.path.join(our_path, '../patman'))
 
-import board
-import bsettings
-import builder
-import control
-import command
+from buildman import board
+from buildman import bsettings
+from buildman import builder
+from buildman import control
+from buildman import toolchain
 import commit
+import command
 import terminal
 import test_util
-import toolchain
 import tools
 
 use_network = True