Makefile stabilization and updates

[greg-szabo]

Summary

• Make the Makefile compile for Windows (required for SRE OKR binary signing)
• Keep the current feature set intact, but improve on how it executes

Problem Definition

The current Makefile's ledger_check target executes even when the target is not called. Along with similar discrepancies, the Makefile does not run on Windows. It has to, if we want to build Voyager with gaiad for Windows, which is a launch requirement.

Proposal

• Fix the check_ledger target to make it run only when it's called.
• Fix the get_tools target to be compatible with Windows.
• Fix the build target on Windows: Version information is lost, gaiad.exe version returns an empty string.
• Make update_gaia_lite_docs optional for the build target. (don't run update_gaia_lite_docs on build #2647)

---

For Admin Use

• Not duplicate issue
• Appropriate labels applied
• Appropriate contributors tagged
• Contributor assigned/self-assigned

[jackzampolin]

Lets go ahead and implement this!

[greg-szabo]

The first PR is about Windows compatibility for the build target and ledger support. It does not address the issue of get_tools yet. Still, it's a complete PR in itself, it should be considered for merging.

[greg-szabo]

The second PR was submitted with a cross-OS compatible get_tools Makefile. This should make our current documentation completely compatible with Windows builds. (mingw32-make get_tools get_vendor_deps build will run on Windows, provided that the basic setup of mingw, git and go are installed.)

Unfortunately, the first PR was not merged yet, so the whole thing is pending on review now. The good news is that it was tested on OSX and Windows and CircleCI ran it successfully for Linux.

[greg-szabo]

Closing this issue. The merged PR resolves all conflicts for Windows builds.