Add information about `package` folder to changelog
Move files out of `arduino-mk` subdirectory

fix #152
Simplify package vs git checkout detection

Fix #147
Fix #151
Fix #153

The following are the detailed changes

- Remove ARDMK_PATH, ARDMK_FILE and arduino-mk subdirectory
- Looks for ard-reset-arduino in $PATH or ARDMK_DIR/bin
- Fix git-archive command in RPM SPEC file
- Remove some whitespace
- Remove arduino-mk dir from debian package's arduino-mk.install
- Update docs to reflect the above changes
- Bump Up version to 1.2.0
Remove `arduino-mk` folder from all examples

Fix #154
Freezing up code for v1.2.0 release