Igniters, As you may know we had only 2 dependencies at ignite-core: jcache and ignite-shmen.
IGNITE-3323 Get rid of copypasted JB annotations, use dependency instead. <https://issues.apache.org/jira/browse/IGNITE-3323> brings one more dependency to org.jetbrains.annotations. This solves problems for people using JB annotations at their projects. but makes ignite-core less dependency-lightweight. JB annotaions are used to highlight null problems in IDE and provide some understanding to users on whether null is allowed/possible in concrete place. I doubt other products/frameworks use it much. But, do we really need them? As for me, we can replace all these annotations by asserts. I propose to discontinue usage of jb annotation and replace them by asserts. Thoughts?
