Encouraging contributions

[Gudahtt]

This project has relatively few contributors, with the vast majority of work being done by @ricmoo. Is this intentional, or would you like to receive more contributions from the community?

It's clear that a lot of time and effort has been spent making this project friendlier to contribute to (e.g. the extensive internal documentation, the contributor docs), but these efforts are offset by many obstacles. Overall I have personally found it quite difficult to contribute.

Some of the problems I encountered are:

• Generated files in the repository.
  The test and build script leave dozens of generated files that the contributor docs recommend not including in PRs. Keeping track of which files to include and which to exclude is tedious and error prone, and it's often difficult to understand what should and shouldn't be included. For example, I was surprised to find out that when updating unit tests, the tarballs needed to be included for tests to pass. A .gitignore file could exclude unwanted files, and can be overridden when the distribution-related files need to be updated.
• Unit test framework and documentation
  The unit tests are difficult to understand. The documentation is impressive, but it has gaps (such as the BigNumber test suite) which caught me by surprise.
• The upcoming major version branch seems to be private
  I cannot find the v6 branch. Keeping this branch private makes it impossible for anyone to contribute to v6. For anyone who submitted a patch that you decide to include in v6, it also obscures how that patch was incorporated and prevents contributors for testing it.

That's just off the top of my head. I'm sure there are more areas for improvement.