Support gradle and maven project in cider-jack-in

[bbatsov]

Right now we properly detect only boot and lein projects, but some people are actually using maven and gradle adding the relevant project type detection logic and nREPL boot commands shouldn't be hard.

Related to clojure-emacs/refactor-nrepl#124

//cc @kotarak

[bbatsov]

Basically, to make some progress on this we need info regarding how maven and gradle users typically boot the nREPL server.

[RadicalZephyr]

For gradle at least this is probably a good place to start looking: https://github.com/clojuresque

[kotarak]

I'm working on the gradle support. I created a pull request for this: #1380. (Please let me know if the flow is different. I usually don't work work with PRs.)

I'm also working on the gradle plugin to provide the necessary interface from the "other" side.

[kotarak]

One question in particular, which is open for discussion in the PR, is the order of preference.

kotarak@9a22027#diff-00bd1ee3b6816bf7f502bc824ec4a6e9R422

[bbatsov]

As I mentioned in the PR - there should be no order of preference; we should simply detect all possible project types and prompt the use to pick one.

You'll have to update clojure-project-root in clojure-mode as well.

[kotarak]

Updated PR with sqashed commit: PR #1391.

[bbatsov]

Gradle support has been merged. I'll close this for now as it's unclear now many people are using Maven with CIDER and I don't want us to just fill the backlog with noise.