Add maven support.
Merge pull request #1 from onlinemad/maven-support

Merge maven support from onlinemad-maven-support branch.

If a developer would like to use maven support, please correct the following fields in the pom.xml.

<gae.version>1.7.7</gae.version>
<gae.home>/appengine-java-sdk-${gae.version}</gae.home>
modify post API method intro
exclude maven target folder
pass some jslint