releasetools: Switch to Python logging.

Converts the following files to Python logging.

add_img_to_target_files.py
blockimgdiff.py
build_image.py
check_ota_package_signature.py
common.py
img_from_target_files.py
make_recovery_patch.py
ota_from_target_files.py
sparse_img.py
verity_utils.py

This separates logging outputs from normal outputs, and allows easier
switching between different verbosity levels. It also supports adjusting
logging config via environment variable (LOGGING_CONFIG).

Test: `m dist`
Test: `python -m unittest discover build/make/tools/releasetools`
Change-Id: Idfc3f7aff83e03f41f3c9b5067d64fd595d5192d
diff --git a/tools/releasetools/img_from_target_files.py b/tools/releasetools/img_from_target_files.py
index 01ff149..0156b72 100755
--- a/tools/releasetools/img_from_target_files.py
+++ b/tools/releasetools/img_from_target_files.py
@@ -28,6 +28,7 @@
 
 from __future__ import print_function
 
+import logging
 import os
 import shutil
 import sys
@@ -39,6 +40,7 @@
   print("Python 2.7 or newer is required.", file=sys.stderr)
   sys.exit(1)
 
+logger = logging.getLogger(__name__)
 
 OPTIONS = common.OPTIONS
 
@@ -72,6 +74,8 @@
     common.Usage(__doc__)
     sys.exit(1)
 
+  common.InitLogging()
+
   OPTIONS.input_tmp = common.UnzipTemp(args[0], ["IMAGES/*", "OTA/*"])
   output_zip = zipfile.ZipFile(args[1], "w", compression=zipfile.ZIP_DEFLATED)
   CopyInfo(output_zip)
@@ -90,11 +94,11 @@
       common.ZipWrite(output_zip, os.path.join(images_path, image), image)
 
   finally:
-    print("cleaning up...")
+    logger.info("cleaning up...")
     common.ZipClose(output_zip)
     shutil.rmtree(OPTIONS.input_tmp)
 
-  print("done.")
+  logger.info("done.")
 
 
 if __name__ == '__main__':
@@ -102,5 +106,5 @@
     common.CloseInheritedPipes()
     main(sys.argv[1:])
   except common.ExternalError as e:
-    print("\n   ERROR: %s\n" % (e,))
+    logger.exception("\n   ERROR:\n")
     sys.exit(1)