Gradle: handle progress events for all interactions with gradle including getting BuildEnvironment model.
Otherwise we can miss gradle tooling client side events like distribution download.

E.g. "The specified Gradle distribution 'https://services.gradle.org/distributions/gradle-version-bin.zip' does not exist."
The error message should be shown for import project and for task execution

test failures caused by incompatible platform guava library which pollutes the classpath (and hence the guava from gradle plugin ignored). The issue affects only test and running IDEA using IDEA. Testing of 1.x should be enabled when the proper plugin classloader will be used for tests

avoid apache libs version conflict for aether module: use httpclient and commons-codec implementations from the IDE distribution

As discussed with UI specialist, there should be 8 pixels between
"Push tags:" and the combobox, and 40 pixels between the combobox
and "Run Git Hooks".
Actual values are smaller due to internal margins of the components.

* Invert "Skip" to "Run hook" since positive options are more clear.
* Place the commit option near other code analysis checks.
* Don't remember the state of the checkbox: it is dangerous to skip
  hooks, so it should be a one-time decision each time.

GitSkipHooksCommitHandlerFactory is defined as a CheckinHandlerFactory,
and not VcsCheckinHandlerFactory to be able to place the checkbox
below all other code analysis checkboxes:
since bc023094, VCS handlers are processed before standard handlers,
but that means that their components are placed also before components
of standard handlers.
On the other hand, the visibility of "Run Git hooks" checkbox
is controlled by its handler, so it is OK to make it a standard
CheckinHandler.

Improvement for IDEA-115914.

Follow-ups the fix for IDEA-115914.

Git supports a `pre-commit` and `pre-push` hooks that are executed
after a commit or a push accordingly (https://git-scm.com/docs/githooks).
Sometimes it's needed to skip the hooks and bypass the checks for them.
For that purpose git supports a parameter `no-verify`.
With that commit inside the git commit dialog a checkbox "Skip hook" will be
available if any of the repositories have a `pre-commit` hook installed.
Similar way in the push dialog it will be possible to bypass the
`pre-push` hook.
Options are not visible and not used when there's no such hooks installed.

Currently only local hooks (inside .git/hooks folder) are supported.
It doesn't support a new git configuration variable `core.hooksPath`
that allows customizing where the hook directory is (since git 2.9.0).

If a test task should be run on Python2.7 and Python3.5, we should run it
only once for each of two interpreter versions.
PyTestTask.getTagsToCover method now serves this need: when all tags that the environment
provides are already covered, we skip the particular environment

Signed-off-by: Vassiliy.Kudryashov <Vassiliy.Kudryashov@jetbrains.com>