Add a script to compile examples as an automated test suite.

* Added script/boostrap.sh to download the Arduino IDE and MPIDE (for
    chipKIT). Tested in Linux, should work in Cygwin and OS X too.
* Added script/runtests.sh to run "make" in each example project and
    collect the results. The script returns -1 if any fails.
* Moved currently testable examples to a "tests" directory, separate
    from examples that require alternative cores.
Add config for Travis CI to run the tests automatically.
Merge pull request #254 from peplin/test-suite-and-ci

Add an automated test runner for example programs and Travis CI integration
Add note about test suite in changelog
Rearrange items in changelog
Add the built status button
Add a note about unit test cases in contributing notes
Document CFLAGS, CXXFLAGS, ASFLAGS and CPPFLAGS.

After understanding the difference between CXXFLAGS and CPPFLAGS, this
is a revised commit for https://github.com/sudar/Arduino-Makefile/pull/257
Merge pull request #263 from peplin/document-flags-vars

Document CFLAGS, CXXFLAGS, ASFLAGS and CPPFLAGS.
Move tests back to 'examples', skip non-testable examples when testing.

This fixes https://github.com/sudar/Arduino-Makefile/issues/259.
Move scripts inside tests directory.

Fixed https://github.com/sudar/Arduino-Makefile/issues/260
Remove old dependencies dir from .gitignore, now stored in /var/tmp.
Merge pull request #268 from peplin/259-move-examples

Move tests back to 'examples', skip non-testable examples when testing.

Fix #259
Fix #260
Removed Travis-CI references from all examples. Regular users
are not affected by test scripts/makefiles.

Added makefile and gcc version info to config output.

Tested on Arduino 1.0.6
Merge pull request #269 from sej7278/fix-travis

Remove Travis-CI references from all examples

Fix #250
Fix #208