Refactored tools structure & conventions for reuse (#685)

1.  All common tools are hosted and managed in
    the tools directory (used for both local development
    and continuous integration)
2.  Each tool comprises a directory, akin to a bundle,
    that encapsulates declarative command-line options,
    configuration files and a run script
3.  A single bootstrap script configures a
    development environment
4.  A lightweight runtime provides a common set of
    convenience functions and variables to all scripts

References #672

.tools/cppcheck/options.sh

@@ -0,0 +1,12 @@
+#!/bin/bash
+
+OPTIONS="--quiet                                      \
+	--error-exitcode=1                                  \
+	--force                                             \
+	--enable=style,information                          \
+	--library=avr                                       \
+	--platform="${TOOLCONFIG}"/avr.xml                  \
+ 	--includes-file="${TOOLCONFIG}"/includes.cfg	      \
+	--suppressions-list="${TOOLCONFIG}"/suppressions.cfg"
+
+echo $OPTIONS