Add global method to convert binary string to plain string
Add global method to convert binary string to plain string

* wqflask/utility/db_tools.py: escape_string returns a binary string which
introduces a bug when composing sql query string. The escaped strings have to be
converted to plain text.

zsloan/genenetwork2,pjotrp/genenetwork2,genenetwork/genenetwork2,pjotrp/genenetwork2,genenetwork/genenetwork2,zsloan/genenetwork2,zsloan/genenetwork2,pjotrp/genenetwork2,genenetwork/genenetwork2,zsloan/genenetwork2,pjotrp/genenetwork2,pjotrp/genenetwork2,genenetwork/genenetwork2