ADXL345 can now set bandwidth

Added setters and getters to bandwidth and also added the tests to
ensure all works.

The makefile.common now includes more warning flags to ensure the code
is well formatted
Added extra warnings

Warnings are now treated as errors, and more warnings such as pedantic
are added.

So the following changes ensure no warnings are thrown due to the new
changes

Note that most of the warnings are due to -Wold-style-cast.
Fixed coloring