Started working on WPT_Importer class (#15).
Added some more documentation to WPT_Importer.
Finished documenting all methods of WPT_Importer.
Added tests for the new WPT_Importer class (#15).
Added a warning to WPT_Importer. Closes #15.
Merge branch 'issue-15' into v0.10
WPT_Importer tests were using deprecated methods.