[Ohrrpgce] SVN: teeemcee/9394 Rewrite safe_shell on Windows so that it doesn't pop up a console window

[subversion at HamsterRepublic.com]

teeemcee
2017-09-18 08:33:19 -0700 (Mon, 18 Sep 2017)
431
Rewrite safe_shell on Windows so that it doesn't pop up a console window.

Hence run_and_get_output is fixed too; this was worst when entering Distribute
Game menu, which could cause a whole lot of console windows to pop up if
utilities were missing from support/. Also complaints about this causing
keys to get stuck.

Before safe_shell just called SHELL, now it uses open_process (ie winapi calls).
Also added wait_for_process().
---
U   wip/os.bi
U   wip/os_unix.c
U   wip/os_windows.bas
U   wip/util.bas
U   wip/whatsnew.txt