Log Message:
Update to 1.19.1

Changelog:
* Changes in Wget 1.19.1

* Fix bugs, a regression, portability/build issues

* Add new option --retry-on-http-error

* Changes in Wget 1.19

* New option --use-askpass=COMMAND. Fetch user/password by calling
  an external program.

* Use IDNA2008 (+ TR46 if available) through libidn2

* When processing a Metalink header, --metalink-index=<number> allows
  to process the header's application/metalink4+xml files.

* When processing a Metalink file, --trust-server-names enables the
  use of the destination file names specified in the Metalink file,
  otherwise a safe destination file name is computed.

* When processing a Metalink file, enforce a safe destination path.
  Remove any drive letter prefix under w32, i.e. 'C:D:file'.  Call
  libmetalink's metalink_check_safe_path() to prevent absolute,
  relative, or home paths:
  https://tools.ietf.org/html/rfc5854#section-4.1.2.1
  https://tools.ietf.org/html/rfc5854#section-4.2.8.3

* When processing a Metalink file, --directory-prefix=<prefix> sets
  the top of the retrieval tree to prefix for Metalink downloads.

* When processing a Metalink file, reject downloaded files which don't
  agree with their own metalink:size value:
  https://tools.ietf.org/html/rfc5854#section-4.2.16

* When processing a Metalink file, with --continue resume partially
  downloaded files and keep fully downloaded files even if they fail
  the verification.

* When processing a Metalink file, create the parent directories of a
  "path/file" destination file name:
  https://tools.ietf.org/html/rfc5854#section-4.1.2.1
  https://tools.ietf.org/html/rfc5854#section-4.2.8.3

* On a recursive download, append a .tmp suffix to temporary files
  that will be deleted after being parsed, and create them
  readable/writable only by the owner.

* New make target 'check-valgrind'

* Fix several bugs

* Fix compatibility issues