Switch to gradle-lesscss-plugin and build fixes

Two main changes here:

 * Remove the Makefile used to compile LESS style sheets and switch to [gradle-lesscss-plugin](https://github.com/obecker/gradle-lesscss-plugin)
   * This eliminates the need to have the NPM less package installed.
   * The dependency on this plugin is also resolved at build time just like other dependency jars.
   * I am working on a Gradle plugin for linkedin-dustjs. Once that is done, then Azkaban will no longer require one to install Node.js and any NPM packages in order to build.
 * Fix problem where running `gradle dist` in a clean source tree (such as after running `gradle clean`) does not copy the Azkaban jars into the lib directories for each of the packages and requires running `gradle dist` a second time before those jars are actually copied.
   * This is caused by the `copy` methods in the `package*` tasks being executed when the build script is initially evaluated (which occurs before any of the Java build tasks are run) rather than when the `package*` tasks are actually being executed.
   * I have also cleaned up all the "deprecated dynamic property" warnings.

The diff would be so much easier to read if GitHub had a side-by-side diff view...