CLN: remove relative imports
This fixed the (motivating) syntax error from #3821, and has the benefit of working on py3 (when not built is show ImportError rather than syntax error). Merge?
 will rebase and then i willl merge
 @jreback good 2 merge?
 what exactly is the reason the relative imports are bad?
 i don't think they are bad necessarily, but they're certainly not needed here since they were used to refer to `pandas`. see [here](http://stackoverflow.com/questions/4209641/absolute-vs-explicit-relative-import-of-python-module) for short pro/con discussion. also the exception being caught here was too general...whenever i have an installation issue it's hidden by a cryptic error message... about not being able to import `hashtable`
 Your error message is a big improvement, (and solves the even less descriptive "syntax error" in py2.5+3).
 also importerrors should not be caught by `except Exception` clauses they should be caught by `except ImportError:` let's call a spade a spade... 
 sounds good then
