Examples module cannot be built due to SNAPSHOT maven dependencies

Currently, `examples` module (in git tree) depends on `-SNAPSHOT` versions of Apache Ignite. This easily causes inability to run them in a way described in README.

A mere user may want to run examples in the following way:

1. Clone source code from Github.
2. Open examples module in IDE
3. Try to run examples using instructions provided

Unfortunately, this will not work because of `-SNAPSHOT` versioning of examples module. Snapshot builds of AI3 modules that examples module depends on are not published on any publicly accessible repository. Hence, instead of working example, user could only get a distracting compilation error.

In theory, there could be 2 ways to deal with it:

1. Only use examples from distribution ZIP file. This version doesn't have `-SNAPSHOT` dependencies, so it could be built easily. Alas, this way is not quite obvious for one who get used to work with OSS via GitHub primarily. In addition, this way is not available for pre-release testing.
2. Build all dependencies (e.g., a whole AI3) from the source locally. Again, it's not documented, and it could really take significant time. And it's still far from the "Import the examples project into your IDE" claim.

Something should be done with it. Possibly, examples module should have its own life cycle (maybe even in a separate repository). Possibly, few additional instructions should be written for solving typical user problems described above.