Make compareRTypes more Ice-like

This converts the compareRTypes from using
raw pointers to Ice smart pointers.
Fix gtest assertions

GTest didn't like assertions of the form
`ASSERT_EQ(false, ...)`. Now using _TRUE
and _FALSE.
Fix rtype comparison using operators

The gt/lt comparisons were all failing in the
rtypes test. By defining the comparator operators,
(here for RString) these now pass.
Implement fixes from rleigh
Add comparison operators for other primitive types

Note: this breaks null proxy checks of the form
`x->getY() == 0`. Use `!x->getY()` instead.
Handle comparisons for RTypeSeq containers
Rename compareRTypeSeq to match compareRTypes
Merge pull request #2444 from joshmoore/cpp-utests

CPP unit test fixes