[treewide] Change some format options

This introduces some formatting style changes. The two key introductions
are:
  - We no longer allow multi-line if-statements without braces, for better
    security practices;
  - Extended column-limit to 100.

The new style rules have been applied to the whole project using clang-format.

Change-Id: I5bbdcf71d48c7a687222f97ecb4e59b989f96d2e