Cease to use Jfrog Anno Mojo maven plugin and use normal maven xdoclet annotations

[adamsiemion]

jcabi-beanstalk-maven-plugin can't be built with Java 8, because we use Jfrog Anno Mojo maven plugin, and it's not ready for Java8 (for details see #17).

It is decided to get rid of Jfrog Anno Mojo maven plugin and use normal maven xdoclet annotations.

(Jfrog Anno Mojo allows to use Java5-style annotations instead of writing them in javadoc comments.
We need to switch back to this comments option.)

You can find the plugin's occurrences in pom.xml by searching for jfrog.

[yegor256]

it's a duplicate of #17

[dmarkov]

@yegor256 only @adko-pl can close this issue, since he opened it

[dmarkov]

I will ask someone to take care of this task soon