Add Select Siblings, Select Same Type, Deselect All [fix-30295]
URLUtil.splitScheme(): rewrite in a more clear way.

* Use method proposed in CR-IC-374
* Change behavior: return the scheme without scheme separator ("://")
[git] Remove unused method and unused field.
IDEA-103544 Recent files popup closes completion popup when invoked by DOWN key
IDEA-102738 Hg reports nothing to push where there is a warning /error about creating a remote head while doing a push

*Change HgErrorUtil.isAbort methos, because "abort" key word may be not only at the last error line of hg output. (check all error lines)
*Update HgPusher.push method using mercurial standart  exit values for success and nothing to push