works on C++11 again
remove unused predicate.hpp, remove trailing whitespace
search_n and tests
remove spurious counter from search_n, fix comments
view::generate and view::generate_n work with functions with non-const function call operators, fixes #26, begin to document design decisions, guidelines, rationale
unique_copy and tests
heap algorithms (untested), misc tweaks
tests for is_heap_until
test for is_heap
tests for push_heap
fix Swappable concept, fixes #29
test pop_heap
test for make_heap
tests for sort_heap