Expose a method to list commands and scoped files

[RomainEndelin]

Expose projectionist#list_all(), an extended version of projectionist#navigation_commands. As mentioned in #32.

[rosshadden]

👍 This is a great idea, and lets us use unite with vim-projectionist!

[tpope]

I think a function that globbed a single projection would more appropriately fulfill the use case, no? This interface forces you to glob all projections (which could be really slow) rather than just one.

[nelstrom]

It looks like @RomainEndelin's fusion.vim (which was the motivation for this PR) is now deprecated, so perhaps this PR can now be closed?

Even so, I think it's a neat idea to make unite (or denite) play nicely with projectionist.

[fsharpasharp]

I'm interested in this pull request, but it does not seem like the globbing in this new function is consistent with the globbing rules that exist. E.g. * does not recursively match subdirectories, might need to replace it with double star.

[RomainEndelin]

Sorry for the extra late reply, this had gone out of my mind until today. As @nelstrom mentioned, I do not maintain fusion.vim anymore, since I'm no longer using it (I even switched from Vim to VSCode).

@fsharpasharp if you want to rework on this PR, you have my blessing 👍 . I'm afraid I won't really be able to help, since I've forgotten every little bit of knowledge I had about VimL over the past two years...