check_target_files_signatures.py was accidentally broken due to the
renaming of a variable in last commit. It escaped the checking from
pylint because it was a keyword ('all').
Bug: 21611858
Change-Id: I58c983e59c4a3e0018481d3c9ba328ed76f5c08a
This caught a few bugs/syntax errors (a few character classes were not
escaped properly in regex patterns, some indentation was illegal,
etc).
Change-Id: I50637607524e68c4fb9cad7167f58a46b8d26b2c