fixed NPE

Do not find actions by ID
Merge remote-tracking branch 'origin/master'
java-decompiler: extra casts on method calls omitted

(loosely based on https://github.com/JetBrains/intellij-community/pull/217)
IDEA-97689 Undo causes code corruption
Treat methods of base class that raise NotImplementedError as abstract
Add 'unittest' package to all Python mock SDKs
Add helper methods 'isObjectClass' and 'isObjectType' in PyUtil
java-decompiler: cleanups and fixes

- duplicates eliminated
- immutable fields
- typos
- formatting
project: inspection settings tuned
project: dictionary extended
Merge remote-tracking branch 'origin/master'
fixed PY-14109 IPython Notebook: propose to configure/start server in-place on trying to run some cell
Merge remote-tracking branch 'origin/master'
Make StepOverAction dumb aware
fix exception in the first suspend in remote debugger
IDEA-131531 Push dialog: it is not clear that push target (remote branch in Git, repository URL in Mercurial) can be modified

* vcsLinkedText used  instead of additional type of components, others removed;
* editable text component interface added as a special type which start tree edit mode;
* linkedText components rendered themselves;
* linkedText components underlined when under cursor or under selection
Merge remote-tracking branch 'origin/master'
unnecessary hierarchy removed
maven: use "idea." prefix for IDEA specific property (maven3.use.compat.resolver)
maven: check for existing project in maven actions. It possible to process actions without an open project
related issue - https://youtrack.jetbrains.com/issue/IDEA-132152