small bug fixed
Merge remote-tracking branch 'origin/master'
[log] remove not entirely correct @NotNull from fields initialized in setup
[log] generify multi repo joiner with commit class

Simplifies usages in the refresher.
[git] fix & simplify parsing of ref names for git log --decorate

tags start with "tag:" prefix => it should be removed.
ContainerUtil.notNullize for Set
[log] VcsLogSorter can accept any Collection, not just List
[log] lessen logging, because it may happen e.g. for origin/HEAD
[log] Load refs and commits synchronously, speed-up git log startup

=> IDEA-126380 avoid diverging of log & refs if they are queried by
   separate commands, and the repository changes between these requests.
=> IDEA-117553 initial startup loading becomes faster.

* Tell plugins to return refs, users and commits altogether, they
  should worry about synchronousness by themselves.
* For Git:
  + call log --decorate=full on refresh, thus getting all
    references which are attached to requested commits.
  + Add all branches there by reading them from branch files.
  + Ignore other tags on startup.
  + On refresh check new tags ('git tag' is fast), and load more commits
    if needed.
  + Ignore rare case if some old tag pointers moved.
  + on startup don't use --decorate for speed-up, instead just read
    branches manually. Some validation will follow.
* Provide trivial implementation for hg.
IDEA-129633 Copy/Paste from image viewer (a=Siva Velusamy)
IDEA-129568 'Tab title limit' setting does not dither out when Tab Placement set to 'None'
IDEA-129319 Settings: gap between header and list of links for a group in Alloy
EDU-150 open all task files on double click in project view
Merge remote-tracking branch 'origin/master'
shortcuts to navigate to prev/next comparison failure
extract light method object: filter inaccessible variables