changed task creation, so that the gradle BasePlugin is used and the xcode clean task is a child of the BasePlugin clean task
Issue #39
add universal library task

Conflicts:
	plugin/src/main/groovy/org/openbakery/XcodePlugin.groovy
fixed that the test output shows also a failed if an exception occurs, and the test crashes

(XcodeUniversalLibraryTask postponed)
now all unit tests are working again
added support for multiple archs as parameter: issue #33
removed some comments
updated the changelog for the new 0.9.2 release
prepared 0.9.2 release