Eliminate _assertPred
 Issue 5870 - Debug code in SortedRange assumes it can always print the range
Update range.d
Merge pull request #2028 from Infiltrator/patch-1

 Issue 5870 - Debug code in SortedRange assumes it can always print the ...
Fix DDoc typo.
Merge pull request #2031 from monarchdodra/ScopeBufferConst

Fix DDoc typo.
Merge pull request #2017 from andralex/datetime

std.datetime: eliminate _assertPred
OutBuffer is now an OutputRange
Merge pull request #2034 from WalterBright/OutBufferToOutputRange

OutBuffer is now an OutputRange
callback uses size_t not double

- Not sure why the curl internal double arguments
  are converted to size_t in the first place though.
Merge pull request #2035 from MartinNowak/fixCurlDocs

callback uses size_t not double