new class: vector and FilteredRange

Adds a std::vector-like class that works on a fixed-size array similar
to gestures::set.
Also adds a FilteredRange class that can be used to create iterable
containers that skip certain elements. This can be used for a helper
method to iterate over all pointing fingers by skipping fingers with
certain flags. In combination with c++11 range-based for loops this
will reduce a lot of repetitive code in the filter interpreter.
Note: This CL changes the compilation standard to GNU C++11.

BUG=chromium:226699
TEST=src/vector_unittest.cc

Change-Id: I4118c92b878923d398513c5d2645da41ab84a395
Reviewed-on: https://gerrit.chromium.org/gerrit/47828
Reviewed-by: Andrew de los Reyes <adlr@chromium.org>
Commit-Queue: Dennis Kempin <denniskempin@chromium.org>
Tested-by: Dennis Kempin <denniskempin@chromium.org>