Provide an "installation" script

[sleberknight]

Rather than having to go into the kiwiproject-changelog repository, build the (shaded) JAR, then run the JAR using java -jar /path/to/kiwiproject-changelog/target/changelog-generator-0.10.0.jar <options>, provide a way to "install" the change log generator.]

The installation script should:

• Checkout and build the most recent (production) release
• Copy the shaded JAR to the installation directory, perhaps specified as an installation option
• Create an executable script, e.g., .generate-kiwi-changelog, in the to the installation directory
• Either add the script to the PATH or provide a snippet to add to a bash/zsh/etc profile

Installation options might include:

• the install directory (perhaps this should be required)
• allow a custom name for the script if someone doesn't like the default name
• automatically update the bash/zsh/etc profiler script to add to PATH

The installation should also allow updating when a new version is released, which would replace the JAR in an existing installation. If the JAR is named generically, i.e., without the version number, then only the JAR needs to be updated.

The installation directory might look like:

<install-dir>/
    .generate-kiwi-changelog
    kiwi-changelog-generator.jar
    README.txt

For initial installation, usage could look like:

$ ./install.sh -d /home/alice/kiwi-changelog

Or to create a custom script name:

$ ./install.sh -d /home/alice/kiwi-changelog -n generate-changelog

To perform an update, you would simply run the install.sh script again:

$ ./install.sh -d /home/alice/kiwi-changelog

The script should be smart enough to detect an update, and only update the JAR.

Then, to run the change log generator, the usage should be pretty simple, e.g.,:

~/Projects/kiwiproject/kiwi-js $ .generate-kiwi-changelog \
    --repository kiwiproject/kiwi-js \
    --previous-rev v0.5.0 \
    --revision v0.6.0 \
    --output-type GITHUB \
    --close-milestone \
    --create-next-milestone 0.7.0

Or, using the short names:

$ .generate-kiwi-changelog -r kiwiproject/kiwi-js -p v0.5.0 -R v0.6.0 -o GITHUB -C -N 0.7.0

[sleberknight]

On a re-installation, we should update everything, in case other things have changed.