Changed JRE version from 1.6 to one's preferred

LibGDX correctly works with JRE 1.7 so I changed this in Eclipse project
files to get rid of many warnings.
Corrected arguments to accord Javadoc
Revert "Changed JRE version from 1.6 to one's preferred"

This reverts commit f4b421cd4ac1c13bba1eab9355ca8b99f3a928cc.
Ignore false warning
Revert "Ignore false warning"

This reverts commit a8e29b5e45e66745a3f3478096cde28cca112026.
Merge pull request #2399 from needhash/master

Fixed Eclipse warnings