support multiple app

see changeling for details

Support download file name in unicode

#22

Enfore adoption of pyexcel 0.2.2

#15
take pyexcel 0.2.2 into use. no longer import pyexcel.ext.xxx is required. manage your pyexcel plugins using pip.

set file name in response

as in pull request #8

Less code lines

• Abstraction has been made to pyexcel-webio

Make response from a database query set

• new function: make_response_from_query_sets

Bring pyexcel to Flask based web development

• extends flask.request with pyexcel's signature functions
• extends flask.make_response to make array, dict, sql tables as excel file download