Before, jbuilder used to stop its execution after an error was
encountered. Now it continues until all branches have been explored.
To implement this feature, Future was rewritten as a Fiber module with
a simpler semantic.
This patch contains various other refactorings.
* docs: update some documentation in the Build module
* docs: document what [Scope.resolve] does
* docs: add a toplevel docstring to the Alias module
* docs: document (or not) the bootstrap function
* docs: lightly document the bootstrap module
* fix ignore comment
- vendored libraries are replaced by files in `vendor/boot`
- files named `XXX.boot.EXT` replace their `XXX.EXT` equivalent
For instance, to build boot.exe, we use `src/glob_lexer.boot.ml`
rather than `src/glob_lexer.ml` (which would be generated from
`src/glob_lexer.mll`).