progress on preassert library
more work on preassert
Merge branch 'staging' into development
add ELIB_THROW as alias for ELIB_THROW_EXCEPTION
progress on preassert
added extra braces to rethrow block macros. Now users can both omit and include braces
increment development version
minor changes
partial changes in new filesystem draft
more filesystem updates
update optional to new proposal with c++1y features
add make_array to aux
move preassert to contract_assert