Better error messages for the namespace argument

Work around when the first arg is -1

When seemingly valid arguments are given for non existent classes,
return a meaningful error message.
Described *1-*3,*e in repl-welcome

I have learned only by chance about the fact that REPL stores evaluation results in *1 - *3 and the last exception in *e. I am certainly not the only one unaware of this so it would be good to include it in the welcome message.

(For random visitors: they are defined in clojure's [`./src/clj/clojure/main.clj`](https://github.com/clojure/clojure/blob/master/src/clj/clojure/main.clj).)
Fix tutorial repl message. Addresses #1317.
Use more descriptive local name.
Use profile-scoped targets in app template.
Don't warn about user profiles when running outside a project.
Warn when nrepl dependency isn't found. Fixes #1330.
Fix typo in lein template invocation command.
Merge pull request #1332 from jconti/master

Fix typo in lein template invocation command.
Better error message for bad -m args.
More descriptive error message for nonexistant ns.

Closes #1257.
Merge in better error messages for -m in lein run.
Fallback to .nrepl-port for 'repl :connect' subtask
Merge pull request #1336 from jcrossley3/connect-via-nrepl-port-file

Fallback to .nrepl-port for 'repl :connect' subtask
Abort with a nicer message when neither port nor .nrepl-port is provided
Merge pull request #1338 from jcrossley3/port-required

Abort with a nicer message when neither port nor .nrepl-port is provided
Merge pull request #1324 from dominikdz/master

Added support of maven <plugin> in pom.xml (pom-plugin tag)
Merge pull request #1310 from jakubholynet/patch-1

Described *1-*3,*e in repl-welcome
Implement `:uberjar-merge-with` requested in issue #973.
Fix unusual/extra whitespace in sample.project.clj.