Two bugfixes for Eclipse-WTP if applied on java project

Hi @radimk,

sorry, but while working on GRADLE-2123 I encountered two bugs which hereby are tested and fixed :-)

Side note: And can you also please comment on http://forums.gradle.org/gradle/topics/additional_eclipse_wtp_facet_overwrites_default_facets?utm_source=notification&utm_medium=email&utm_campaign=new_reply&utm_content=reply_button&reply[id]=15040558#reply_15040558, what strategy would fit Gradle best? Possibilities:
* Adding a method to add the default facets, or 
* adding a method to clean default facets before adding a new one, or
* let it like it is (as soon as adding a new facet, the defaults are gone)?