Fix missing initialization in Constructor.

[ya1gaurav]

OurFeatures() Constructor is not initializing variable rejectDupKeys_.

[pavel-pimenov]

cppcheck 1.69
Member variable 'OurFeatures::stackLimit_' is not initialized in the constructor.
Member variable 'OurReader::stackDepth_' is not initialized in the constructor.

[BillyDonahue]

pavel has a point. Maybe go a little further and initialize the other fields while we're here.

[ya1gaurav]

stackLinit_ initialized in #364
It wil make OurFeatures to be free from above cppcheck , other pull request can be done for OurReader.

[cdunn2001]

Instead, let's delete the whole ctor. We can accept C++ defaults b/c they are always over-ridden in newCharBuilder().

But yes, let's update the OurReader ctor. I don't want to refactor that class since it is mainly a copy of old code.