Adding quick test for #1136.

* Just checks to see if + in version numbers are removed from pom files.
Fix #1136 - Ivy's `+` dependencies not converted to maven style syntax.

* Attempt to convert dependencies that end in `+` into maven-style version range
* if a failure occurs, just use the original version (could be bad...).
Pull in @cunei's suggestion for a more complete Ivy->Maven dynamic revision convertor.

   We attempt to convert these constructs to maven:
   * 1.+
   * ]1,2]
   * [2,3[
   * 1+  - Albeit this one is a heuristic for accuracy.

This should help ivy users which prefer the nicer 1.2.+ syntax.

Also adds tests/improves exisitng tests.
Merge pull request #1145 from sbt/wip/issue-1136

Fix #1136 - Ivy's + dependency ranges not converted appropriately to maven.