Target code self-signing done by a generic post-build step

[treeswift]

New core MXE features:

• mxe.postbuild.sh with enough information passed in to extract the files created by a single (component x target) build.

New packages:

• openssl in host configuration;
• osslsigncode (host binary) — open source Portable Executable signing tool;
• snakeoil (data only) — silent issuance of self-signed code-signing and timestamping certificates;
• popen2 (duplex popen()) and faketime — dependencies of osslsigncode;

New dependencies:

• llvm-mingw depends on snakeoil (host configuration).

[treeswift]

Setting -j to anything greater breaks the build because the generated Makefile contains implicit dependencies. Was the case with the MXE 7.0.0 version of OpenSSL too.

[pahaze]

Ah, gotcha. Happens with a lot of projects for some reason, at least from what I've noticed