Add --sysroot to ccflags etc so that make in ExtUtils::MakeMaker etc will use it
Revamp usecrosscompile section.
Use sysroot for libpath/incpath if set.
Set to/from/run scripts if targethost is passed, regardless of whether we are cross compiling
Set appropriate flags for linux or linux-like systems.
Add missing $run prefix to some Configure tests
Stop using $run for anything other than testing compiled tests in Configure.
(When cross-compiling we want to run miniperl etc on the compile host, not the test target)
No xconfig.h is produced when cross-compiling, we have a normal config.h
Setup $^O to be the target os when building Core.
This allows the correct hints files to be loaded when building modules
Stop using Config{run} to check the version of (mini)perl we are running
Build host miniperl and generate_uudmap binaries when cross compiling, for local use
Force removal of existing files in host/ dir when building new miniperl (cross-compiling)
Fix accidental bashisms introduced into Configure
Run all the miniperl calls remotely, not via RUN
Fix Makefile so that host dir is removed in make distclean
Remve extra "was file copied" check using run-ssh, this doesn't seem to be of much use.
Also introduce $targetport to allow running on a non-standard ssh port (such as when
using user networking on qemu and redirecting a local port to the emulator ssh)
Cope with osnames that look like "*linux*" which happens when cross-compiling.
Re-organise the creation of Config.pm to allow $^O to be "osname" from config.sh, instead of miniperl's $^O.

This is necessary when cross-compiliing, as we use a host (mini)perl to run configpm for the target arch.
add an escape for when targethost is not defined but usecrosscompile is.
fix the ability to use targethost when defined.
write_buildcustomize.pl now uses Config, so add a Makefile dependency.
Makefile.SH, write_buildcustomize.pl: Pass in the osname

This means that write_buildcustomize.pl no longer depends on
Config, which eliminates a circular dependency.