The motivation to upgrade this host-tool is to fix a compile-time warning:
[4890/10620] Generating boot/bootdata/...oot/bootdata/system, boot/bootdata/BCD
Binary hive maker
->RegDeleteKeyW(0x0xcab210, '') is UNIMPLEMENTED!
[145/10684] Generating boot/bootdata/BCD
Binary hive maker
Creating binary hive: /home/jhenze/Release_WorkDir/Repo/output-MinGW-i386/reactos/boot/bootdata/BCD
Thw warning was most likely introduced when we started using mkhive in the hosttools, and is triggered
by livecd.inf having a [DelReg] section.
Warning fixed by implementing RegDeleteKeyW().
It can not delete full trees yet, but we also don't need that for our mkhive-usage yet.
While touching it, do also fix some other minor glitches and leaks.
This is a PARTIAL backport of the 15 commits from 0.4.11-dev, all to mkhive from 2018-10-09 to 2018-10-20 by hbelusca.