First try at leiningen general purpose integrated command line

Conflicts:

	ccw.core/build.properties
Lein command line: better reach from anywhere in Eclipse
Switch to leiningen 2.1.2 and official parsley 0.9.1
Launch clojure app: uses leiningen when facing a leiningen project

Conflicts:

	ccw.core/.gitignore
lein app launcher debug session:

- launch shortcut works for editor selection
- ClojureLaunchShortcut does less (it took care of too much responsibility,
  thus leading to different behaviours when configurations launched from
  shortcuts of from list)
- repl is now started from any means to launch configuration

Conflicts:

	ccw.core/build.properties
	ccw.core/plugin.xml
Creating manually a launch configuration from an editor selection works

Conflicts:

	ccw.core/src/java/ccw/util/StringUtils.java
Cleanup.

Type parameters added; Unnecessary variable and branches removed;
Used Interface instead of class
Avoid NPE.

REPL view can be missing.
(At all other call sites result of getProjectREPL call
is checked for null.)
Fix issue if project had run configurations created by versions < 0.13
New configurations created with additional security: specific name
Warning message if a launch is still present without replview.

- Normally, this is impossible
normalized dependency on ccw.server (not named ccw-server anymore)
Removed file ccw.repl.cmdhistory.prefs from git
Add leiningen-standalone.jar, replace tools.nrepl-*.jar with lib/tools.nrepl.jar
Deactivation of Launcher based on external leiningen process.
ChangeLog update
Update build.properties

Fixed jars packaged into `ccw.core` plugin
Temporary addition of leiningen-standalone.jar to git
More debug traces for tracking issues with new leiningen launcher, etc.
feat(plugins): Support for user plugins in $HOME/.ccw

Arbitrary contributions to the Eclipse 4 Model can be made, or
modifications to ccw vars.

- every folder under $HOME/.ccw containing 1+ clj file is a plugin folder
- the plugin folder is added as a classfolder in CCW's classpath ...
- ... while each clj file at the root of the plugin folder is loaded
  (no guarantee on the order)
- contributions to the Eclipse 4 Model can be made via the ccw.e4.dsl
  macros
- any contribution provided by a previous load of the plugin that is not
  reinstalled during the plugin load is automatically removed from the
  model (only works for Commands and Handlers ATM)