Merge pull request #29 from khorser/master

Keep original .tar.gz when ungzipping
Eanble some 'hoogle data' functionality for 'hoogle convert'
Merge pull request #31 from khorser/convert-improved

Eanble some 'hoogle data' functionality for 'hoogle convert'
typo of "equivalent"
Merge pull request #32 from juhp/patch-2

typo of "equivalent"