rapps_new: Port SHA1 checking code

Port the SHA1 checks from rapps that swyter created to rapps_new.
Tested on Windows and ReactOS,
builds with msvc and gcc (on Windows)

To the reviewer:
Please note, i had to edit lib/cryptlib/sha1.h (near the very end of the patch) to be able to use the A_SHA* functions from c++.

swyter: I changed the flow of VerifyInteg to no longer use goto, hope you don't mind