Mos 1769: The core project does not build the correct differential tree for some very similar trees

See #30, release log:

• abb55a7 by @kniazkov: + tests
• 0a25bba by @kniazkov: + tests
• 6368a13 by @kniazkov: + tests
• d984054 by @kniazkov: Fixes 1679 bug
• 85bd9d1 by @kniazkov: Extended node builder
• e49aa15 by @kniazkov: ExtNode interface
• ffa1be0 by @kniazkov: The fix works, however it is h...
• 7486bdf by @kniazkov: Fix Qulice warnings
• 45fd9ae by @kniazkov: Action static converter

Released by Rultor 2.0-SNAPSHOT, see build log