more work on counted ranges appendix
fix return value of numeric tests
More work on proposal, tighten up SizedIteratorRange concept
counted sentinels are empty, faster counted iterators
benchmark insertion_sort for counted ranges
minor suggestions after fast read
add perf benchmark for counted ranges, use ADL to find advance overloads, fix handling of single_pass in view cursors
uncounted and recounted are found by ADL
merge gnzlbg/draft_suggestions, with edits
Merge pull request #45 from gnzlbg/test_fixes

fix return value of numeric tests
factor out iterator distance/enumerate from range distance/enumerate
set algorithms (UNTESTED), use std::atomic with cached state in slice and stride views to avoid race conditions
includes algorithm and tests
tests for set_difference, fix bug in lexicographical_compare
test for set_intersection
concepts work
tests for set_union
Merge remote-tracking branch 'upstream/master' into push_back