added helper function which generates a working parameter and function pair.
Merge pull request #37 from Tillsten/make_minimizer

[EHN] Possible helper function to easily create parameters and a function to use them
changed add() and add_many() to match order in argument order in doc
improved Python3 support
start (incomplete) support for local version of uncerrtainties package
more on adding and using local version of uncertainties package
moved operators to asteval.py
expanded Parameter defn
uncertainties now propogated to constrained variables
bugfix for setting internal/external transform of bounded parameters now that inf/-inf are used
improve PEP-8 / pylint improvements
updates to doc
returned to relative import of minimizer in confidence.py
fix typos in confidence calculations
tweaks to doc
Merge branch 'master' of git://github.com/newville/lmfit-py
make_para... now works like intended, added test and to init