adding MIT license to root of repository

13 Java files are explicitly under the MIT license, while the rest
don't specifically state anything. Hopefully it's all MIT and this
clarifies some things :)
adding some helpful links to README
Merge pull request #11 from sghill/update-readme

adding some helpful links to README
Merge pull request #10 from sghill/add-license

adding MIT license to root of repository
ignoring IntelliJ files in git
JENKINS-19872 add configuration options for console output link
[FIXED JENKINS-19872] extracting duplicate strings into LinkStyle class
Merge pull request #13 from sghill/JENKINS-19872

[FIXED JENKINS-19872] add configuration options for console output link
Merge pull request #12 from sghill/gitignore-intellij-files

ignoring IntelliJ files in git
[JENKINS-19872] fix checkstyle plugin errors, introduced in PR #12
adding quick build instructions to README
Merge pull request #15 from sghill/readme-build-instructions

adding quick build instructions to README
[FIXED JENKINS-19896] removing unprocessed -moz prefixed css declarations

specifically: -moz-box-shadow, -moz-border-radius, -moz-opacity, and
-moz-text-overflow.

unprefixed box-shadow has been supported since firefox 4.
see: https://developer.mozilla.org/en-US/docs/Web/CSS/box-shadow

unprefixed border-radius has been supported since firefox 4.
see: https://developer.mozilla.org/en-US/docs/Web/CSS/border-radius

unprefixed text-overflow has been supported since firefox 7.
see: https://developer.mozilla.org/en-US/docs/Web/CSS/text-overflow

unprefixed opacity has been supported since firefox 1.
see: https://developer.mozilla.org/en-US/docs/Web/CSS/opacity
Merge pull request #14 from sghill/checkstyle-warning

[JENKINS-19872] fix checkstyle plugin errors, introduced in PR #13
Merge pull request #16 from sghill/FIX-JENKINS-19896

[FIXED JENKINS-19896] removing unprocessed -moz prefixed css
Merge branch 'master' of https://github.com/jenkinsci/build-pipeline-plugin into retry-parameter-fix