Fixed a bug in getCellData when you have a render function for a column

variable ind was not defined.
I fixed the bug, but I think that for optimization the parameter ind
should be passed to getCellData, or perhaps removed from the render
function in fields…
Fixed a bug in popup, If you have a form inside

If you had a form in a popup, you could not enter data with the
keyboard because events where not passed to the form due to the
preventDefault…
Now only the escape character is prevented...
Merge pull request #194 from catodique/master

Fixed a bug in w2grid.getCellData and in w2popup.doKeyDown