project.clj: add exclusion for sisu-inject-plexus

Fixes:

Recalculating Leiningen's classpath.
Failing dependency resolution because
[org.apache.maven.indexer/indexer-core "4.1.3" :exclusions [[org.apache.maven/maven-model] [org.sonatype.aether/aether-api] [org.sonatype.aether/aether-util]]] -> [org.sonatype.sisu/sisu-inject-plexus "1.4.3"]
is overrulling
[leiningen-core "2.0.0-SNAPSHOT"] -> [com.cemerick/pomegranate "0.0.13" :exclusions [[org.slf4j/slf4j-api]]] -> [org.sonatype.aether/aether-connector-wagon "1.13.1"] -> [org.sonatype.sisu/sisu-inject-plexus "2.2.3"]
Please use [org.apache.maven.indexer/indexer-core "4.1.3" :exclusions [[org.apache.maven/maven-model] [org.sonatype.aether/aether-api] [org.sonatype.aether/aether-util]] :exclusions [org.sonatype.sisu/sisu-inject-plexus]] to get [org.sonatype.sisu/sisu-inject-plexus "2.2.3"] or use [leiningen-core "2.0.0-SNAPSHOT" :exclusions [org.sonatype.sisu/sisu-inject-plexus]] to get [org.sonatype.sisu/sisu-inject-plexus "1.4.3"].Failing dependency resolution because
[org.apache.maven.indexer/indexer-core "4.1.3" :exclusions [[org.apache.maven/maven-model] [org.sonatype.aether/aether-api] [org.sonatype.aether/aether-util]]] -> [org.sonatype.sisu/sisu-inject-plexus "1.4.3"] -> [org.codehaus.plexus/plexus-utils "2.0.5"]
is overrulling
[leiningen-core "2.0.0-SNAPSHOT"] -> [com.cemerick/pomegranate "0.0.13" :exclusions [[org.slf4j/slf4j-api]]] -> [org.sonatype.aether/aether-connector-wagon "1.13.1"] -> [org.codehaus.plexus/plexus-utils "2.0.7"]
Please use [org.apache.maven.indexer/indexer-core "4.1.3" :exclusions [[org.apache.maven/maven-model] [org.sonatype.aether/aether-api] [org.sonatype.aether/aether-util]] :exclusions [org.codehaus.plexus/plexus-utils]] to get [org.codehaus.plexus/plexus-utils "2.0.7"] or use [leiningen-core "2.0.0-SNAPSHOT" :exclusions [org.codehaus.plexus/plexus-utils]] to get [org.codehaus.plexus/plexus-utils "2.0.5"].Failing dependency resolution because
[org.apache.maven.indexer/indexer-core "4.1.3" :exclusions [[org.apache.maven/maven-model] [org.sonatype.aether/aether-api] [org.sonatype.aether/aether-util]]] -> [org.sonatype.sisu/sisu-inject-plexus "1.4.3"] -> [org.codehaus.plexus/plexus-classworlds "2.2.3"]
is overrulling
[leiningen-core "2.0.0-SNAPSHOT"] -> [com.cemerick/pomegranate "0.0.13" :exclusions [[org.slf4j/slf4j-api]]] -> [org.sonatype.aether/aether-connector-wagon "1.13.1"] -> [org.codehaus.plexus/plexus-classworlds "2.4"]
Please use [org.apache.maven.indexer/indexer-core "4.1.3" :exclusions [[org.apache.maven/maven-model] [org.sonatype.aether/aether-api] [org.sonatype.aether/aether-util]] :exclusions [org.codehaus.plexus/plexus-classworlds]] to get [org.codehaus.plexus/plexus-classworlds "2.4"] or use [leiningen-core "2.0.0-SNAPSHOT" :exclusions [org.codehaus.plexus/plexus-classworlds]] to get [org.codehaus.plexus/plexus-classworlds "2.2.3"].
Improve trampoline help.
Fix repl tests.
Debug output in apply-task.
Allow repl profile to be overridden from project.clj. Fixes #789.
Load plugins in set-profiles. Fixes #772.
Add support for:

* namespaced keywords to control lookup of credentials in env vars
* using a vector to define a number of credential sources to be checked in series

(gh-768)
re-add support for :creds :gpg, add warning for anyone using e.g. :username :gpg to get all creds for a repo (gh-768)
docs update for changes to resolution of repository credentials (gh-768)
Support subtask specific help via 'lein help task subtask'

The help task will first look for static help under
'leiningen/help/task-subtask', then for a function name 'help-subtask' in the
subtask's namespace, then a docstring on the subtask function. For the latter
two options, the arglists are also printed.
Merge pull request #803 from tobias/help-for-subtasks

Support subtask specific help via 'lein help task subtask'
Minor tutorial improvements
Merge pull request #807 from technomancy/mk-tutorial-improvements

Minor tutorial improvements
move hooke-injection closer to where it is used
rename profile-key-merge to meta-merge
add leiningen.core.project/make

Move some defproject logic out of the macro into project/make.
move dependency and repository merging into meta-merge

This is accomplished with the :reduce metadata, which specifies the
reduce function to use when merging. This allows us to merge
dependencies and repositories deeply like other structures. Note that
dependencies are transformed into a map before they are merged and then
transformed back into a vector.

Also change the way that collections are merged. They used to be merged
by taking the right collection and prepending it to the left collection.
This behavior was needed for :*-paths in defproject, but it is not an
obvious default. Now, the default is to append the right collection, but
the :prepend metadata can be used to tell meta-merge to prepend instead.
By default, :source-paths, :resource-paths and :test-paths have :prepend
set to true.
switch with-profile to last-wins

This patch switches with-profile so that the last profile specified
wins. This is more in line with the way clojure.core/merge works.

For more info, see:
http://librelist.com/browser/leiningen/2012/9/12/changing-with-profile-from-first-wins-to-last-wins/#ff32b118546fa95d0960f2247e190c18
keep track of :active-profiles when merging

This is a list of all named profiles that have been merged in, after
following composite profile. This is different from :included-profiles
which is the list of profiles before composite profiles have been
expanded.
Merge pull request #810 from technomancy/last-wins

change with-profile from first-wins to last-wins