This change is fixing "All Java build rules should be loaded from
Starlark" warning flagged by latest buildifier version: [1]. Python
rules are now also loaded from the Starlark.
Also extract codemirror library import to BUILD file. This is needed to
avoid cycle in the workspace file, after importing java rules from
Starlark.
[1] https://github.com/bazelbuild/buildtools/blob/master/WARNINGS.md#native-java
Change-Id: I36192c9465d988b25cf09c250e110f15850910cd
The memory cache doesn't depend on H2 at all, and this separation of
packages makes it harder to reintroduce the kind of source-level
dependency that was removed in I570fd54adf.
Change-Id: Ie23e39cd7ea9a0813a914e65614b889c248342ae