Bug 1408795 - Turn off Eclipse CDT's "Ensure newline at the end of file" setting. r=botond

The setting to ensure that there is a newline at the end of files when they
are saved is very annoying.  Besides adding unnecessary and unexpected cruft
to diffs, some parts of the codebase (some of the reftest directories for
example) have a policy of NOT having a newline at the end of their files.

MozReview-Commit-ID: IjIYxDsKS13

python/mozbuild/mozbuild/backend/cpp_eclipse.py

@@ -701,6 +701,7 @@ org.eclipse.cdt.core.formatter.use_tabs_only_for_leading_indentations=false
 """
 
 STATIC_CDT_UI_PREFS="""eclipse.preferences.version=1
+ensureNewlineAtEOF=false
 formatter_profile=_Mozilla
 formatter_settings_version=1
 org.eclipse.cdt.ui.formatterprofiles.version=1