set release data for v 1.3.3

a few doc updates

dociument changes for 1.3.2.

update whatsnew for 1.3.1

whatsnew for version 1.3.0

final updates for v 1.2.2

spellchecked whatsnew

add modelresult.userargs and userkws to doc

Merge pull request #860 from lmfit/param_vary_setter

make Parameter.vary a property

Merge pull request #858 from lmfit/v120_rc1

update whatsnew, add discussion of data coercion