Bug 959921 - Add lldb command to print an Element's tag name. (DONTBUILD) r=ehsan
Bug 959922 - Add lldb command to print an object refcount. (DONTBUILD) r=ehsan
Bug 959923 - Add lldb alias to dump the JS stack. (DONTBUILD) r=ehsan
Fix ftl lldb alias; no bug. (DONTBUILD)
Add documentation about the lldb commands and type summaries available; no bug. (DONTBUILD) rs=ehsan