In some cases this will introduce cycles which could likely be cleaned
up by only depending on some unix tools instead of the whole autotools.
Rebuilding doesn't make much sense at this point since it just adds a subset
of base-devel which is still installed by default.
It will rebase any *.{dll,so,oct} except usr/bin/msys-2.0.dll. Note it
requires the rebase db to be present, so essentially it requires
rebaseall to have been run (probably at install).
This can never have worked since "paths-from-unix-to-windows" was never installed/packaged.
I'm also not quite sure what the initial goal was based on the git history, so remove it for now.
The implicit `.` (current working directory) in PATH can cause the script to
call a wrong dash/bash if present alongside the installer.
Fixes https://sourceforge.net/p/msys2/tickets/141/
* upgrade some broken packages
* correct some broken urls/checksums
* use secure urls where possible
* use stable url for ncurses
* some whitespace fixes
Remaining md5sums either didn't download or
didn't pass checksum tests.
