Significantly speedup simple for_each, for_loop, and transform

Future/sender adapters

Pinned memory is required for asynchronous memory transfers.

Retry CDash submissions on failure

Fix bogus deprecation warnings with GCC 10

This is to allow transparent overrides of the functionalities for datapar, etc.

- flyby: convert prefetch functionality to use new customization point

- flyby fix problem in prefetching iterator

Polling functions can signal if they still have work to
do (polling_status::busy) or if they are...

Fix typo in docs

Adopt format in more places

It's not possible to provide formatting options to cpu_mask as it changes in type and nature dep...

Correcting target ids for symbol_namespace::iterate

Separate segmented algorithms for transform_reduce

Separate segmented algorithms for transform

clang-format-9 insists on the weird indentation.

Leverage no_unique_address for member_pack

P1897 when_all

Support annotations in hpx::transform_reduce

Install HPX in Rostam Jenkins jobs

Making late command line options available for local runtime

Moving last files unrelated to parcel layer to modules

Flyby: move senders and receivers whenever possible in tests.

Making sure late command line options are recognized as configuration options

Add utility to format ranges

- flyby: move tests into modules

Allow for HPX algorithms being invoked with std execution policies

Only find Boost.Iostreams if required for plugins

P1897 operator| overloads

Banish <iostream> from library headers

Also make P1897 algorithms customization point objects, expand tests for
transform, sync_wait.

This header adds the global std::cin/cout/cerr and wide counterparts to the users' translation u...