Revert "INFRA-68; remove compiling-ide module (#1766)"

[mkuznyetsov]

This reverts commit fd4fa31. related to #1766

What does this PR do?

Going back to have a module for compiling GWT for IDE, and another module for it's assembly. It is needed, to be able to reuse GWT sources in other assemblies (like archetype samples), as well as keep assembly-ide-war clean

What issues does this PR fix or reference?

Changelog

This reverts PR #1766

Docs PR

codenvy/docs#86

[skabashnyuk]

@bmicklea @JamesDrummond note after we merge this pr
Docs and changes log from #1766 this pr have to be reverted too.

[skabashnyuk]

Right now we trying to solve a couple of issues.

1. We want to not to include gwt dependencies that need for gwt compilation in resulting war.
2. We want to include runtime(not gwt related) jars in resulting war.
3. We want to be able to have a single artifact so plugin developers can include it to his gwt compiling war.
4. In future we would like to decentralize gwt.xml between many maven artifacts.

In this pr #1766 we solve 1-2 but forget about 3.
I also have discussion about maven structure of gwt compiling with @benoitf and @vparfonov
During this discussion we have an idea to create uber jar with gwt dependencies but it conflicts 4 Other idea was to keep gwt dependencies as provided but generate classes war dependency during build. But it require to write new maven plugin and we decided to postpone this task.