Don't wrap testTerm() with default arguments

The code is clearer without the extra function and with explicit
arguments.
Add unittest for 12540
Merge pull request #2078 from ntrel/byLine-testTerm

[trivial] Simplify byLine unittest code
Merge pull request #2074 from dymk/fix-12540

Add unittest for 12540
Fix complexity in red-black tree documentation

For the existing implementation front() and opSlice() are O(1).
Merge pull request #2081 from Safety0ff/patch-2

Fix complexity in red-black tree documentation