Add a Bitdeli badge to README
Add 'skip' configuration option.

Includes integration tests
moved options around
[maven-release-plugin] prepare release v2.1.8
[maven-release-plugin] prepare for next development iteration
Update README.md
Allow to limit git properties exposed; WIP
whoops, fix
verified
readme about new feature in 2.1.9

resolves #91
[maven-release-plugin] prepare release v2.1.9
[maven-release-plugin] prepare for next development iteration
Add a help mojo.

This adds an additional goal to the plugin: help

mvn pl.project13.maven:git-commit-id-plugin:2.1.8-SNAPSHOT:help

displays an overview of the plugin and its function.

mvn -Ddetail=true -Dgoal=revision pl.project13.maven:git-commit-id-plugin:2.1.8-SNAPSHOT:help

displays detailed help for the revision goal.
README update
Fixed a problem with XML chars in git log output. Fixes for a code style.